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TVSI was founded in May 1966 as the first Lie Detector Test company in the Philippines. It was a business partnership between CWO Chandler F. Williams, Capt. Conrado G. Dumlao and Dr. Alcyone Thor Reyes. In 1973, the company was incorporated, and in 1985 it opened its US office.

Now, it continues to service the government and private sector as well as individuals, local and foreign in reducing criminality through its expertise in surveillance, process serving, polygraph tests, forgery detection, products.


To maintain expertise, exemplary performance, excellence, and leadership in the field of private investigation in the Philippines. To continue to adhere to the code of ethics set up by international and national professional associations and licensing government agencies.


To render quality service to clients through expert investigative techniques and utilization of modern and scientific evidence gathering technology.

To render truthful and timely reports.

To render truthful and timely reporting of gathered information.

We keep the identities of all of our customers confidential. However,our client roster includes many of the top Corporations in the Philippines, who we have helped save a lot of money. Our clients also include many smaller businesses, individuals, and a number of government agencies with our expertise in surveillance, undercover work, process serving, lie detector test, forgery detection, etc.