Select Page

Private Investigators Bangkok

Since 1994 – Competitive and Realistic rates in Bangkok & Pattaya – All of Country

Rated as one of the best private investigations companies in the world.

WITH HEADQUARTERS IN LONDON & REGIONAL OFFICES. all our local employees and subcontractors are compliant with Thailand’s private investigation regulations, holding the necessary permits in accordance with the provisions set out by Thai law.

Full services Agency for private clients, business, lawyers, families and VIPs.

LOI Investigations established investigators since 1994 with an independently audited 98.9% success rate (March 2024). LOI Investigations offers a comprehensive range of services tailored for the Bangkok market. We cater to private individuals, businesses, corporate investigations & intelligence, Crypto Currency and Bitcoin pre-due diligence, missing-stolen funds tracing and recovery. Offering services that range from Background Checks & KYC to Technical Counter Surveillance Measures. Our Surveillance solutions are led by former military intelligence officers, ensuring the highest level of professionalism. We provide tailored solutions that meet the unique legal landscape of Bangkok including Relationship Matters, Family Law issues, Supply Chain – Risk & Fraud. We also offer Global Database Access and Asset Tracing & Fraud services for comprehensive investigative needs. Additionally, we provide full services for all types of investigations involved. Our team includes local field investigators covering the whole of Thailand and South East Asia, as well as private detectives and private investigators.

Difficult and unusual cases, hidden and hard to obtain information. 
Totally confidential.

Call now for a free consultation

International Free Toll: + 44 800 1 934 999

Calls answered 24hrs a day by qualified local private investigators based in Bangkok

Why Choose LOI Local private investigators in Bangkok?

  • Originally established and trading since 1994.
  • Experienced Team: Recognised worldwide leading investigation and intelligence professionals, also including former military intelligence officers and senior surveillance experts.
  • Tailored Solutions & Advance Technology: Each service is customized to meet the unique challenges and objectives of our private, business, and multinational clients.

Business Intelligence

Critical for strategic corporate decisions, our business intelligence and due diligence services are integral to navigating acquisitions, mergers, and forging new partnerships. We provide in-depth insights and analyses to inform and empower your significant business moves.

Asset Tracing & Recovery

Specializing in asset tracing and fraud detection, we offer customized solutions to uncover hidden assets and fraudulent activities. Our expertise is crucial in safeguarding your financial interests and ensuring the integrity of your transaction

Background Checks

In the complex business environment of Bangkok, thorough background checks and KYC services are indispensable. Our comprehensive approach extends to detailed vetting processes, ensuring reliability and compliance in your business dealings.

Cyber Security Investigations

In an era where digital threats loom large, our advanced cyber security and intelligence services offer robust protection against a spectrum of cyber risks. From combating cyber threats to implementing technical counter-surveillance measures, we ensure your digital assets and operations remain secure.

Deep Level Due Diligence

Deep Level due diligence, also known as enhanced due diligence or ‘boots on the ground,’ is a specialized service offered by Line of Inquiry. Our local investigators provide site visits in-country, customs, and regulatory knowledge, supplementing Level 3 due diligence investigations. Our process involves identifying, evaluating, and verifying information on a person, company, or entity, essential for hiring, business partnerships, or new commercial relationships. With advanced technological tools and certified private investigators, Line of Inquiry leads in deep-level due diligence, ensuring quality data and better performance in the market.

Litigation Investigations & Support

At Line of Inquiry, we specialize in litigation investigation and support services, offering worldwide assistance for both civil and criminal cases. Our experienced team conducts investigations into fraud, breach of contract, intellectual property theft, and more, utilizing advanced technology and techniques. With services including witness interviews, background checks, surveillance, and forensic accounting, we work closely with clients and legal teams to provide expert analysis and testimony, maintaining the highest level of professional and ethical standards.

missing persons investigation

Missing Persons Tracing

Searching for a missing person in Bangkok or worldwide? LOI Investigations offers private investigator services to locate lost friends, family members, or debtors. Utilizing the latest investigative techniques, our experienced team provides effective and discreet missing persons investigations.


Private Clients

We at Line of Inquiry offer a range of services for private clients, including missing persons tracing, background checks, surveillance, and asset tracing. Specialized services are also available for relationship matters, identity theft, and blackmail. Our experienced team utilizes advanced investigative techniques to provide effective and discreet solutions tailored to individual needs.


Line of Inquiry offers a comprehensive suite of services tailored for businesses. These include business intelligence, asset tracing, debtor tracing, and competitive intelligence. Specialized services extend to acquisition and mergers, investment intelligence, and supply chain risk mitigation. Our experienced team employs advanced technological tools and investigative techniques to ensure your business stays ahead in a competitive market.

Relationship Matters & Family Issues

Comprehensive support in family law matters, including relationship disputes and divorce cases. Our services extend to missing persons tracing, surveillance, and personal protection against blackmail. Utilizing advanced technology and an experienced team, we offer discreet and effective solutions tailored to the unique challenges faced by families.

Cyber Investigations

We offer a comprehensive range of Cyber Investigation services, including tackling catfishing, social media harassment, and cyber threats. Our expertise extends to cryptocurrency investigations and technical counter-surveillance. Utilizing a team of former FBI agents, and hacking specialists, we provide robust solutions to protect both individuals and businesses from various cyber risks.


We at Line of Inquiry specialize in litigation investigation and support services, offering worldwide assistance for both civil and criminal cases. Our services include fraud investigations, asset tracing, and family law support. Utilizing advanced technology and techniques, we work closely with legal teams to provide expert analysis and testimony, adhering to the highest ethical standards.

Contact Us

For expert private investigation and intelligence consultancy services in acquiring hard-to-obtain confidential information globally, look no further.