Company lists · Data refreshed September 2026

Top 25 Investigative research firms worldwide

Name: Investigative research firms worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 3,967 companies tracked

RevenueBase identified 3,967 investigative research firms worldwide as of September 2026 and tracks 30,108 professional contacts across them, including 6,687 with verified work emails. The United States is the largest market and London the largest hub.

This list covers investigative research firms worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 2026. Country and city lists for investigative research firms follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review

3,967Companies

30,108Contacts tracked

6,687Verified emails

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The 25 largest investigative research firms worldwide

Ranked by team size

Top 25 of 3,967 investigative research firms worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to investigative research firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Omniplex World Services Corporation	Partial evidence	Herndon, VA, United StatesHQ checked Sep 20, 2026	1,001-5,000	677 contacts →
	Partial evidence “OMNIPLEX World Services Corporation is a leader and innovator in delivering professional background investigations, intelligence support, and physical security services to…” Source: RevenueBase Database · checked Sep 20, 2026
2	DK Security	Partial evidence	Grand Rapids, MI, United StatesHQ checked Sep 20, 2026	1,001-5,000	572 contacts →
	Partial evidence “DK Security is unique in that it offers a single company for a wide ranging availability of security and investigative services.” Source: RevenueBase Database · checked Sep 20, 2026
3	High Beam Global HBG	Partial evidence	Gurugram, IndiaHQ checked Sep 20, 2026	51-200	546 contacts →
	Partial evidence “HBG is a market intelligence firm offering insightful, validated & high quality qualitative & quantitative research data solutions to clients across the globe.” Source: RevenueBase Database · checked Sep 20, 2026
4	Coventbridge Group	Partial evidence	Jacksonville, FL, United StatesHQ checked Sep 20, 2026	501-1,000	518 contacts →
	Partial evidence “CoventBridge Group is the leading worldwide full service investigation solutions company providing: Surveillance, SIU and Compliance, Claims Investigation, Counter-Fraud Programs…” Source: RevenueBase Database · checked Sep 20, 2026
5	Vcheck	Partial evidence	New York, NY, United StatesHQ checked Sep 20, 2026	201-500	336 contacts →
	Partial evidence “Vcheck is a global investigations firm that helps institutions protect their investments by providing intelligence on individuals and entities.” Source: RevenueBase Database · checked Sep 20, 2026
6	Digistream Investigations	Partial evidence	Davis, CA, United StatesHQ checked Sep 20, 2026	201-500	327 contacts →
	Partial evidence “DigiStream Investigations is a full-service private investigation firm specializing in insurance defense and legal support services.” Source: RevenueBase Database · checked Sep 20, 2026
7	Colvill Banks LTD	Partial evidence	Fareham, United KingdomHQ checked Sep 20, 2026	201-500	309 contacts →
	Partial evidence “Colvill Banks are experts in candidate research and identification.” Source: RevenueBase Database · checked Sep 20, 2026
8	HUB Enterprises, INC	Partial evidence	Broussard, LA, United StatesHQ checked Sep 20, 2026	501-1,000	292 contacts →
	Partial evidence “HUB Enterprises is a national insurance defense investigative firm.” Source: RevenueBase Database · checked Sep 20, 2026
9	Guidepost Solutions	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	201-500	268 contacts →
	Indirect evidence “We stand at the forefront of leadership, insight, and guidance in a world marked by complexity and uncertainty.” Source: RevenueBase Database · checked Sep 20, 2026
10	Icover Services	Indirect evidence	Paris, FranceHQ checked Sep 20, 2026	201-500	264 contacts →
	Indirect evidence “iCOVER Group provides high-quality Third-Party Background Screening, Monitoring, and Due Diligence services.” Source: RevenueBase Database · checked Sep 20, 2026
11	Iiris Consulting Pvt. LTD	Indirect evidence	Gurgaon, IndiaHQ checked Sep 20, 2026	51-200	218 contacts →
	Indirect evidence “IIRIS operating under its distinct business offerings "IntelliRisk"(IR),"IntelliSense"(IS),"Security Design" and "Brand Protection" seeks to provide comprehensive intelligence…” Source: RevenueBase Database · checked Sep 20, 2026
12	Frasco	Indirect evidence	Irvine, CA, United StatesHQ checked Sep 20, 2026	201-500	214 contacts →
	Indirect evidence “Frasco has hundreds of investigators and regional offices located throughout the country.” Source: RevenueBase Database · checked Sep 20, 2026
13	Advantage Investigations	Partial evidence	Kannapolis, NC, United StatesHQ checked Sep 20, 2026	201-500	214 contacts →
	Partial evidence “Advantage Investigations is a nationwide leader in the industry for investigative services.” Source: RevenueBase Database · checked Sep 20, 2026
14	Alpine Intel	Indirect evidence	Charlotte, NC, United StatesHQ checked Sep 20, 2026	1,001-5,000	203 contacts →
	Indirect evidence “Alpine Intel is dedicated to innovation across the property, auto, liability, and workers' comp insurance fields-helping our customers reach peak performance throughout the policy…” Source: RevenueBase Database · checked Sep 20, 2026
15	Aeon Research	Partial evidence	Delhi, IndiaHQ checked Sep 20, 2026	1,001-5,000	202 contacts →
	Partial evidence “Aeon Market Research Pvt.” Source: RevenueBase Database · checked Sep 20, 2026
16	Quadrant Strategies	Indirect evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	179 contacts →
	Indirect evidence “Quadrant Strategies helps the world’s most prominent companies navigate their most important brand, reputation, and product challenges.” Source: RevenueBase Database · checked Sep 20, 2026
17	Vmak Research & Services, LLC	Partial evidence	Noida, IndiaHQ checked Sep 20, 2026	51-200	175 contacts →
	Partial evidence “Vmak Research & Services, LLC is a full service Market Research agency specializing in Technology spaces, Telecom, Consumer Products, Media and Healthcare.” Source: RevenueBase Database · checked Sep 20, 2026
18	DE LA Riva Group	Partial evidence	Mexico Df, MexicoHQ checked Sep 20, 2026	51-200	171 contacts →
	Partial evidence “De la Riva Group is one of the most trusted market research companies serving Fortune 500, private and government clients in North and South America.” Source: RevenueBase Database · checked Sep 20, 2026
19	Neotas	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	159 contacts →
	Indirect evidence “By leveraging cutting-edge technology and experienced analysts, Neotas are going beyond and setting new standards in Due Diligence, Staff Screening, and Compliance.” Source: RevenueBase Database · checked Sep 20, 2026
20	Promark Research Corporation	Partial evidence	Spring, TX, United StatesHQ checked Sep 20, 2026	51-200	152 contacts →
	Partial evidence “Promark Research Corporation is headquartered in Spring, Texas, a few miles North of Houston.” Source: RevenueBase Database · checked Sep 20, 2026
21	Cleveland Research Company	Partial evidence	Cleveland, OH, United StatesHQ checked Sep 20, 2026	51-200	151 contacts →
	Partial evidence “Cleveland Research Company is an independent research firm headquartered in Cleveland, Ohio.” Source: RevenueBase Database · checked Sep 20, 2026
22	Information Discovery Services LLC	Partial evidence	Fort Worth, TX, United StatesHQ checked Sep 20, 2026	51-200	146 contacts →
	Partial evidence “A federally qualified Small Business, IDS offers end to end investigative solutions tailored to meet the specific needs of our clients.” Source: RevenueBase Database · checked Sep 20, 2026
23	PSA	Partial evidence	Washington, DC, United StatesHQ checked Sep 20, 2026	51-200	142 contacts →
	Partial evidence “PSA is a global due diligence and investigations firm headquartered in Washington, DC.” Source: RevenueBase Database · checked Sep 20, 2026
24	Trendsource, INC	Indirect evidence	San Diego, CA, United StatesHQ checked Sep 20, 2026	11-50	141 contacts →
	Indirect evidence “TrendSource helps businesses document and measure compliance across employment, consumer reporting, government, finance, health care, and retail.” Source: RevenueBase Database · checked Sep 20, 2026
25	Corporate Research And Investigations	Strong evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	140 contacts →
	Strong evidence “Corporate Research and Investigations Limited is a global provider of investigative research, background screening and business due diligence services for the world’s leading…” Source: RevenueBase Database · checked Sep 20, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: investigative research firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names investigative research firms.
Partial evidence: Its own public description names part of investigative research firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name investigative research firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 3,967 investigative research firms worldwide

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Investigative research firms worldwide at a glance

As of Sep 20, 2026

22.2%Verified-email coverage

7.6Average contacts per company

1-10Median size (employees)

2.2%Largest-city concentration · London

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

2,539

11-50

1,007

51-200

291

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency is reported on each country list linked below.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among investigative research firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
Coverage: Every country. Country and city lists for investigative research firms are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “investigative research firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names investigative research firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among investigative research firms, and records with no verified work email.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 6,687 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 20, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Investigative research firms by location

13 lists · largest first

Every Investigative research firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names investigative research firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many investigative research firms are there worldwide?

RevenueBase identified 3,967 investigative research firms worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Omniplex World Services Corporation, headquartered in Herndon, tops this list with the largest team on record.

Which country has the most investigative research firms?

The United States leads with 1,750 companies, followed by the United Kingdom (221) and India (209). Every investigative research firms list by country and city is linked on this page.

Which city has the most investigative research firms?

London leads with 87 headquartered companies, followed by New York (59) and New Delhi (46).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 6,687 verified decision-maker contacts tracked across these 3,967 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 20, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.