Defence has now launched an inquiry into how the barmaids, nicknamed "Skimpis", had reappeared at the Special Air Service (SAS)'s Gratwick Club this year despite an order banning them being issued last year.

The topless barmaid tradition became public earlier this week after the mother of the bisexual soldier alleged her son was put under investigation because of his sexuality while serving at the base known as Campbell Barracks.

She argued a double standard was occurring in her son's case and, as proof, released photos of topless barmaids at the club also known as "Grattos" and which is described on a government website as a "Commonwealth Government Entity".

In an initial response to the mother's complaint, Defence claimed that the practice of topless barmaids working at a club was stopped in 2013 after commanders were made aware of their presence.

But late yesterday Defence revealed that topless barmaid events had resumed this year. "Command direction was given in June 2013 to immediately cease activities of this nature. It now appears that these events recommenced on an infrequent basis in 2014," said a spokesperson. "Command and senior personnel within the unit had not been aware of this and are inquiring into how such functions recommenced despite command direction they cease".

The original investigation into the bisexual soldier, who was serving at Campbell Barracks, revolved around his alleged purchase of peptides and occurred only after his sexuality became known among other troops around Anzac Day, his mother says.

The mother said another soldier, who had issues with her son's sexuality, was suspected of making a vexatious complaint about peptides. She said her son purchased the peptide type substance from an Australian company believing it to be legal and that Defence had so far failed to provide any proof that what he purchased was illegal at the time.

The soldier's mother said he had sought the peptide to assist his recovery of a painful back injury sustained when his vehicle was blown up in Afghanistan. It was part of his effort to maintain fitness that would allow him to remain in the army. Defence has declined to provide further details about the soldier's case or his identity.

But a spokesperson said Defence was focused on the soldier's well-being and was reviewing the allegations featured in the media reporting.

"The use of prohibited substances by Australian Defence Force (ADF) members is incompatible with an effective and efficient Defence Force as it can undermine healthy, safety, discipline, morale, security and reputation," the spokesperson said.

Peptides are amino acid-like proteins that are supposed to help build muscle mass and speed up repair of muscle injury.

They recently provoked controversy after their use was found to have been promoted among professional athletes. Grattos, which is frequented by the SAS troops who have done the majority of fighting in Afghanistan was established in the 1950s and named after World War II Victoria Cross winner Percy Gratwick.

The ADF was recently the subject of a series of inquiries in relation to sexual, physical and mental abuse following revelations of a major sex scandal at the Australian Defence Force Academy in Canberra involving a video of a female cadet having sex that was broadcast to a group of male cadets.

Last year, army chief David Morrison issued a stern warning to personnel after dozens of soldiers were linked to the distribution of emails denigrating women. "I will be ruthless in ridding the army of people who cannot live up to its values," General Morrison said.