Select Page

Private Investigation Services in Japan

Since 1994 – Competitive and Realistic rates. PEACE OF MIND-CERTAINTY

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

With headquarters in London and regional offices, all our local employees and subcontractors in Japan are compliant with Japan’s private investigation regulations, holding the necessary permits and licenses as required by Japanese 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 uniquely tailored for the Japan market including Tokyo and Osaka . We cater to private individuals, businesses, corporate investigations & intelligence, Crypto Currency and Bitcoin pre-due diligence, missing-stolen funds tracing and recovery. Offering an array of services that span from Cyber Security / Intelligence to Technical Counter Surveillance Measures. Our Business Intelligence And Due Diligence services are indispensable for high-stakes business activities such as acquisitions, mergers, and new partnerships. Specialising in Asset Tracing & Fraud, we deliver customised solutions attuned to the intricate business landscape of Japan including Relationship Matters, Family Law issues, Supply Chain – Risk & Fraud , Asset Tracing & Fraud Investigation, Background Checks, KYC services and Global Database Access. Unlike other locations, our operations extend across Asia, Europe, Australia, the UK, and North America, supported by local field investigators to ensure on-the-ground expertise.

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 Japan

Why Choose LOI Local private investigators in Japan?

  • 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

LOI Investigations supplies vital Japan investigation services and business intelligence to medium-sized corporations in Japan and abroad. Utilizing advanced technological tools, we investigate competitors’ processes, practices, research, development, services, and products. Our intelligence is crucial for significant business moves such as acquisitions, mergers, and new partnerships, leading to better performance and positioning in the market.


At Line of Inquiry, we offer in-house surveillance investigators led by experienced professionals, including a former military intelligence officer and a Senior Surveillance officer with 23 years’ experience. Our surveillance services, available across Singapore and worldwide, include mobile and static solutions, under-cover work, and the use of advanced technology such as trackers, electronic bugs, and military-grade drones. Whether discreet or covert, our fool-proof method ensures professional evidence gathering to meet your needs.

Background Checks

LOI Investigations specializes in accurate and thorough background checks for individuals and companies. Offering pre-employment background checks, including verification of education, employment history, and criminal record checks, our experienced private investigators ensure the safety and security of your business and personal life. Trust LOI Investigations for reliable Private investigation services Singapore with confidentiality and fast turnaround times.

Cyber Security Investigations

Line of Inquiry offers Cyber Security Investigation services to thwart planned cyberattacks and minimize damage. Utilizing advanced monitoring, intelligence procedures, and in-depth data analysis, we stay ahead of potential cyber threats. Our capabilities extend to accessing information from the dark web, aiding in criminal investigations, fraud, and identity theft cases. Our innovative tools and methods, combined with AI-backed automation and expert human expertise, enable us to identify different types of threats and build defense systems tailored to individual business needs.

Stolen Jewellery, Art, and High-Value Items Investigation Room

Jewellery Theft

At LOI Research, we specialize in the recovery of stolen jewellery, art, and high-value items. Our dedicated team of private investigators is renowned for their expertise in tracking and recovering valuable items that have been lost or stolen. Our services are not just limited to the UK; we operate globally, providing our clients with the best chance of recovering their valuables.

Global Database Access

Line of Inquiry offers Global Database Access, providing lawful access to limited-access technical, commercial, regulatory, financial, and legal databases. This service enables clients to make informed decisions based on facts, whether for financial, legal, commercial, or other technical needs. Leveraging a network of connections, Line of Inquiry ensures that data is accessible for legal purposes, aiding businesses and organizations in various applications.
missing persons investigation

Missing Persons Tracing

Searching for a missing person in Japan 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.