Company lists · Data refreshed November 2026

Top 25 Private investigation services worldwide

RevenueBase identified 3,767 company matches for private investigation services worldwide as of November 2026 and tracks 21,888 professional contacts across them, including 3,394 with verified work emails. The United States is the largest market and London the largest hub.

This list covers company matches for private investigation services worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026. Country and city lists for private investigation services follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
3,767Companies
21,888Contacts tracked
3,394Verified emails
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The 25 largest private investigation services worldwide

Ranked by team size
Top 25 of 3,767 company matches for private investigation services worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchGrand Rapids, MI, United StatesHQ recorded Nov 6, 20261,001-5,000592 contacts →

Exact match

“DK Security is unique in that it offers a single company for a wide ranging availability of security and investigative services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchJacksonville, FL, United StatesHQ recorded Nov 6, 2026501-1,000377 contacts →

Exact match

“CoventBridge Group is the leading worldwide full service investigation solutions company providing: Surveillance, SIU and Compliance, Claims Investigation, Counter-Fraud Programs…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchDavis, CA, United StatesHQ recorded Nov 6, 2026201-500359 contacts →

Exact match

“DigiStream Investigations is a full-service private investigation firm specializing in insurance defense and legal support services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchKannapolis, WA, United StatesHQ recorded Nov 6, 2026201-500225 contacts →

Exact match

“Advantage Investigations is a nationwide leader in the industry for investigative services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchIrvine, CA, United StatesHQ recorded Nov 6, 2026201-500222 contacts →

Exact match

“Frasco has hundreds of investigators and regional offices located throughout the country.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchNew Delhi, IndiaHQ recorded Nov 6, 20265,001-10,000181 contacts →

Exact match

“Globe Detective Agency (P) Ltd.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchFort Worth, TX, United StatesHQ recorded Nov 6, 202651-200152 contacts →

Exact match

“A federally qualified Small Business, IDS offers end to end investigative solutions tailored to meet the specific needs of our clients.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchLos Angeles, CA, United StatesHQ recorded Nov 6, 202651-200143 contacts →

Exact match

“Alias Intelligence is a leading background investigations and due diligence company delivering the information and insights our clients need to grow and navigate their businesses.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchNorth Haven, CT, United StatesHQ recorded Nov 6, 2026501-1,000138 contacts →

Exact match

“Knowledge is power" Whether you are an insurance company, TPA, insurance defense law firm, risk manager, private law firm, or corporation / business owner, we at Lemieux &…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchNew York, NY, United StatesHQ recorded Nov 6, 202651-200130 contacts →

Exact match

“Beau Dietl & Associates is a premier private investigation firm based in New York City with offices in New Jersey, Florida, and California.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchNew York, NY, United StatesHQ recorded Nov 6, 202651-200121 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchChevy Chase, MD, United StatesHQ recorded Nov 6, 202651-200108 contacts →

Exact match

“MSM Security Services, LLC (MSM) is an experienced company providing Investigative Services, Risk Analysis and Screening support for business and employment requirements.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchUnited StatesHQ recorded Nov 6, 2026201-500104 contacts →

Exact match

“Why Becker & Company?”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchTroy, MI, United StatesHQ recorded Nov 6, 2026201-500101 contacts →

Exact match

“The Robison Group is an agency of professional investigators and support teams offering surveillance, SIU claims, business risk mitigation and comprehensive desktop investigation…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchSão Paulo, BrazilHQ recorded Nov 6, 202651-20097 contacts →

Exact match

“Somos uma empresa de Investigação e Inteligência Corporativa conhecida nacionalmente por seus resultados em Recuperação de Veículos, Consultas Anti-fraude, Monitoramento Veicular…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchHuntington Beach, CA, United StatesHQ recorded Nov 6, 202651-20094 contacts →

Exact match

“Horsemen Investigations is a full service investigation company, specializing in investigating insurance fraud and in minimizing risk exposure.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchNew York, NJ, United StatesHQ recorded Nov 6, 2026201-50091 contacts →

Exact match

“AJ Squared Security, Inc.(AJ2), is a privately owned security organization founded in May 2003 and incorporated in November 2003.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchUnited StatesHQ recorded Nov 6, 202611-5088 contacts →

Exact match

“Corporate Surveillance”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchCilandak Barat, IndonesiaHQ recorded Nov 6, 202651-20079 contacts →

Exact match

“Integrity Indonesia, established in 2001, provides reliable fraud prevention, detection, and investigation services to organizations across Southeast Asia and beyond.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchNew York, FL, United StatesHQ recorded Nov 6, 2026201-50075 contacts →

Exact match

“Integrated Security Services, Inc.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchBrisbane Cbd, AustraliaHQ recorded Nov 6, 202651-20073 contacts →

Exact match

“With a history dating back to 1979, Risk & Security Management is Australia’s leading provider of mercantile and investigation services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchMonaca, PA, United StatesHQ recorded Nov 6, 2026201-50073 contacts →

Exact match

“CSI is a full-service investigative firm that delivers key facts to give our clients an actionable advantage in a wide range of situations.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchWashington, DC, United StatesHQ recorded Nov 6, 202611-5070 contacts →

Exact match

“Investigative Group International (IGI) is the premier investigative firm conducting independent, high-touch investigations worldwide.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchToronto, ON, CanadaHQ recorded Nov 6, 202651-20068 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchWoburn, MA, United StatesHQ recorded Nov 6, 2026201-50066 contacts →

Exact match

“Claims Bureau USA has been providing Insurers, TPA's and their defense counsel with quality, in-depth investigative services since 1956.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 25 of 3,767 private investigation services worldwide

See the full list, filter by size, metro and specialty, and access 3,394 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Private investigation services worldwide at a glance

As of Nov 6, 2026
15.5%Verified-email coverage
5.8Average contacts per company
1-10Median size (employees)
1.7%Largest-city concentration · London
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
2,599
11-50
768
51-200
248
201-500
68
501-1,000
14
1,001-5,000
8
5,001-10,000
1
10001+
5

Email recency is reported on each country list linked below.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
Coverage
Every country. Country and city lists for private investigation services are linked below.
What qualifies
Company records worldwide whose business descriptions match “private investigation services” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 3,394 professional contacts with verified work emails across the full matched dataset. 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 November 6, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Private investigation services by location

9 lists · largest first

Every Private investigation services 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 SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “private investigation services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many private investigation services are there worldwide?

RevenueBase identified 3,767 company matches for private investigation services worldwide as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

DK Security tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most private investigation services?

The United States leads with 1,831 companies, followed by the United Kingdom (215) and Italy (199). Every private investigation services list by country and city is linked on this page.

Which city has the most private investigation services?

London leads with 63 company records, followed by New York (39) and New Delhi (35).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 3,394 professional contacts with verified work emails tracked across these 3,767 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 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 SmartSearch, 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.