Sydney - The death of a young American mathematician whose naked body was found at the bottom of a Sydney cliff was a gay hate crime, a coroner found on Thursday following a string of judicial probes.The finding in a case that has long fascinated Australia comes after three inquests, and almost 30 years since Scott Russell Johnson died in December 1988 aged 27, with police at that time ruling his death a suicide.Only one other time in Australian history have three inquiries been held into a single case – after the death of Azaria Chamberlain, a baby snatched by a dingo from a campground."I am of the view that it is very unlikely that Scott intentionally took his own life," New South Wales state coroner Michael Barnes said in his ruling."Mr Johnson fell from the cliff top as a result of actual or threatened violence by unidentified persons who attacked him because they perceived him to be homosexual."Citing evidence he had reviewed, Barnes said there were gangs of men in Sydney at the time who "habitually went to various locations... to find homosexual men with a view to assaulting them".One "gay beat" spot was Blue Fish Point in Manly, near the cliff top where Johnson's clothes were found neatly folded. "I am persuaded to the requisite standard that Scott died as a result of a gay hate attack," Barnes added."There is however, insufficient reliable evidence to identify the perpetrators."Johnson's brother Steve, who had long pushed for further probes, said a homicide investigation should be pursued."It is a historic time in Australia for the LGBTQ (Lesbian, Gay, Bisexual, Trans and Queer) community, for everyone," he told the Sydney Morning Herald, with Australia set to change laws in favour of gay marriage after a national survey endorsed reforms."I think the police should be free to investigate this as they know how to do, focusing on homicide, which is something they haven't really done in the past."NSW Police said the case remained open and any new information "will be thoroughly investigated".