The British Navy launched a secret investigation in the 1960s because it was so alarmed by evidence that sailors were involved in homosexual romps in Bermuda and Singapore.

A previously secret Navy report from 1969, which was made public in London yesterday, stated that a man in Bermuda would give sailors presents to take part in gay sex acts and to pose for pornographic pictures in his home.

The report states that more than 400 sailors were involved in the activity on the Island.

The document from the British Public Records Office released yesterday notes a local man in Bermuda regularly invited sailors to his flat "giving them presents for partaking in grossly indecent acts and posing for sexually perverted photographs".

"Almost every single one interviewed stated that he would not like his exploits to be known to near and dear ones," stated the document, adding there was a risk of blackmail.

The report also states that British sailors going out on the town in Singapore regularly used male prostitutes and "lady boys" - gay hookers dressed as women.

Nights on the town "not infrequently end up with them sleeping with male prostitutes...who dress up very convincingly as females".

A document written by a navy medical director described the Asian prostitutes as "very beautiful. They dress well and smell delicious. They perfect the female walk, go to surgery to complete the illusion. Quite a high percentage of intelligent men could be fooled, even when sober".

Commander in Chief of the Western Fleet Sir John Bush wrote in 1969: "There is, regrettably, ample evidence that homosexual practices are rife in the fleet."

Despite exhaustive studies, the navy found no way of dealing with the problem. Bush wrote: "In all this I have virtually no concrete recommendations to make", adding that all he could suggest was "constant and persistent education".

A Ministry of Defence memo released yesterday from the time, states: "Apart from discouraging homosexual practices on the messdeck and elsewhere, what can a leading hand (sailor of higher rank) do about it?"