Seemingly omnipresent, the former officer says they posed as ice-water sellers, sweepers or street vendors. Some undercover officers even pretended to be, in his words, "lunatics".
In 2008, Myanmar's military rulers crafted a new constitution, which allows greater political freedoms and opposition parties to contest three-quarters of seats in the parliament. The remaining quarter are guaranteed to military officers.
Myanmar has been changing fast. The nation's major cities are now lively. Investment is flowing in while construction and tourism are flourishing. There is a vibrant media.
One topic that remains a mystery is what the secret agencies are up to now.