Official silence, a veil of secrecy and even outright disbelief about wartime sex among servicemen has reigned supreme ever since, compounded by mythologies about Aussie diggers and the ''mateship'' legend. Now, historians are telling a different, more realistic story thanks to the release of an army file on the discharge of male homosexuals in WWII. During investigations over the past two years, researchers Yorick Smaal and Graham Willett gained almost complete access to the National Archives file, first released in 1992 but in a heavily edited form that revealed little. One of the key episodes outlined in the fuller file is about a series of incidents in New Guinea in late 1943 involving a group of self-identifying homosexual - or ''kamp'' - men. The records include the life stories of 18 of these soldiers, who were interviewed by a major after they were reported for illicit sex by a United States defence investigator. The soldiers' names and identifying material have been withheld, but the file details how army authorities, for the first time, began to tackle the idea that there was a difference between homosexual behaviour and homosexual identity. Dr Willett, a senior lecturer at the University of Melbourne's Australian Centre, suspects that the men agreed to tell their stories in detail in exchange for a medical discharge rather than a dishonourable one.

The historians, whose research was partly funded by the Australian Army History Unit, say they had long suspected homosexuality in the armed services was far more common than traditionally acknowledged. They initially pieced together fractured accounts from novels, diaries, memoirs, oral histories and official records. The accounts include ''situational sex'' between men - ''making do'' because there were no women around, so that ''butch'' men might have sex with ''queens'' with no loss to their masculine status. This is possibly the case with some of the 1945 ''jungle juice'' soldiers in Borneo. Other incidents the researchers came across involved a more clearly articulated homosexual identity. The stories in the National Archives file, however, are different to those other sources: they not only give extraordinary insight into the lives of homosexual men on the frontline, but also detail their first sexual experiences, relationships and friendships, sex lives, army experiences and their relationships with each other and the American soldiers stationed nearby. The file, and other New Guinea research material, reveals such things as wild sex parties in the jungle, regular sexual horseplay, and liaisons with American soldiers in old shower blocks. ''Sex was certainly central to their wartime experience and the Americans were particularly prized,'' says Dr Smaal of those 18 soldiers. An historian from Griffith University, his PhD on sexuality in WWII sparked his research with Dr Willett. '' 'Trade' were often found at the bar at the American Red Cross at Ela Beach where a large 'kamp' crowd hung about. Some Americans would often take half a dozen Australian 'girls', as they were known, out to the bush by jeep or truck where sex would take place. There were usually about 15 US men to six 'girls' at these parties and it was common for the Australians to have more than one partner a night to keep the men satisfied.''

Dr Smaal says the role-playing of the ''girls'' in New Guinea was shaped by commonly held notions of the day about sexuality and gender. ''They were, in the words of the US army provost who alerted Australian officials, men who 'practised the female side of homosexuality'.'' In one excerpt from the army files, a soldier recounts how he would go about with other ''kamp'' men, visiting the American Red Cross at Ela Beach. ''Several times we were 'picked up' by Australian or American soldiers. Once or twice we went along the beach, other times we went in parties in trucks into the bush. We had relations with them.'' Others spoke of how ''Aunties'' took less-experienced men under their wings and taught them the ''tricks of the trade''. While Dr Smaal says the ''girls'' were simply one group of Australians - most likely there were also butch Australians going with effeminate Americans - it just so happens this is the group they have found out about. ''The evidence is so fractured, so we have to be cautious about extrapolating too far,'' he says. ''But clearly what is happening in New Guinea is a mirror of what is happening back on the home front and that is quite clear in the interviews. All the ideas playing out in New Guinea about their sense of self and sense of identity are the same that are happening back in Sydney, Brisbane or Melbourne. It is not an isolated instance.'' The jungle sex parties were discovered by the US Army provost in what Dr Smaal describes as a witch-hunt. ''The American army has certainly got a pedigree with that sort of activity,'' he says. The provost had worked with a vice squad, ''so he knew what he was looking for - the signs and codes of the 'perverted practices' he was seeking out''. Gore Vidal, the late American author and US Army veteran in the Pacific, is quoted in Dennis Altman's Coming Out in the Seventies, as saying that Australian soldiers ''had a reputation for rolling over on their stomachs most obediently''. This sort of account, including Robert Hughes's reports of widespread convict-era homosexual practices in The Fatal Shore, often meets with stern denial along the lines of ''there were no poofters in the armed services''.

But in historian Frank Bongiorno's new book The Sex Lives of Australians: a History, it is suggested as likely there were considerably more instances of homosexual activity in the defence forces than have survived the record because, when discovered, it was possibly dealt with ''quietly and informally, so as not to draw attention to its embarrassing presence''. This, remarkably, was not the case in New Guinea. Dr Willett says the commander of Australia's military forces in New Guinea wrote anxiously to Melbourne headquarters and wanted to know what to do after the US told him about what was happening among the men. When alerted to the ''problem'', the top brass spent several months debating the causes and how to respond, being unsure whether to use legal or medical approaches. ''The existence of several different (and often opposing) conceptions of homosexuality at work in the army - namely disciplinary, medical and moral discourses - presented commanders with a variety of policy outcomes,'' says Dr Smaal. ''Working their way through this problem, the army became one of the first Australian institutions to grapple in a practical way with the differences between homosexual behaviour and homosexual identity.'' The defence forces, though, probably worried that the incidents in New Guinea might indicate a much bigger ''problem'', so all the commanders around Australia were contacted to try and get a sense of its scope and how to handle it. ''New Guinea was a flashpoint that got Melbourne [headquarters] thinking about homosexuality and identity and how it was playing out in the rank-and-file and how to deal with it. They realised this was about homosexual people rather than homosexual behaviour.'' This, he says, was a radical change to the past. ''If you go all the way back to that idea of the Australian legend, that idea of sublimated mateship and male friendship that lends itself so well to the army as an institution - there was very little inquiry or interrogation into the shifts between platonic and emotional bonds between men and perhaps where that blurs into something more physical or intimate.''

Many of the soldiers in New Guinea and Borneo in the mid-1940s are probably now dead, but Dr Smaal says a sense of self must have been awakened for some of them. ''It must have been quite a revelatory experience, putting them in touch with feelings and desires that they were unable or unwilling to explore on the home front. It might have confirmed their sense of identity and desire for other men. For some men, they wouldn't be prepared to go back to the lives they were living before the war; they wanted to go back and live with their best friends and lovers.'' As one soldier reports in the files, after first joining the army and having sex with eight or nine other soldiers in his unit, he ''ran about a lot'' enjoying many sexual adventures but, five weeks before giving his statement he had met an Australian at the American Red Cross. ''I am greatly in love with him, he returns my love and has asked me to live with him in later life. This I have promised to do.''