The Newtown Local Area Command officers were the subjects of a six-month investigation into drug use in 2015, allegedly instigated by their boss, which involved drug testing, behavioural tests and surveillance in bars.

Shane Housego, Christian McDonald, Steven Rapisarda and Christopher Sheehy have now launched legal action against Mr Fuller, the then assistant commissioner, in the NSW Civil and Administrative Tribunal.

They argue Mr Fuller was indirectly liable for the homosexual discrimination of their boss, as the then head of professional police standards, but that he also failed to address evident discrimination.

For the first time, it can be revealed that the author of a complaint linking the men's "indiscriminate sexuality" with alleged drug taking was made by their superior, Superintendent Simon Hardman.

The complaint said the four men were close friends who visited the gay Sydney venue Stonewall and that drug use was "thought to be fundamental" to the "notorious promiscuity" of two of the men.

Lawyers for the police commissioner lost a bid to keep Mr Hardman's name secret.

Barrister John Fernon, SC, argued revealing the name would contravene a law designed to protect the anonymity of legitimate complainants.

But tribunal head David Robertson ruled it was in the public interest to know the identity of the complainant if he was senior to the men named.

The officers under investigation had previously been told they were the subject of an "anonymous" complaint about drug use and only discovered the extent of their surveillance through freedom of information requests.

The investigation into drug taking found nothing and the men, believing Mr Hardman targeted them because they were gay, made their own complaints to Mr Fuller about "false and malicious" allegations.

"The discrimination we allege is then Assistant Commissioner Fuller's failure to investigate," the barrister acting for the men, Brett Eurell, told the tribunal.

He said complaints by his clients had been met with obfuscation by police.

According to allegations against the men, they shaved their bodies and heads to stop police from taking drug samples and avoided work when they anticipated testing.

Mr Eurell said he expected the tribunal would hear from police standards officers that they had deliberately come to Newtown police station on days they knew the four men would be working.

On Wednesday afternoon, the tribunal was due to hear from one of the four men allegedly targeted, Mr Rapisarda. Lawyers for Mr Fuller did not make opening remarks.