Eurovision song contest winner Conchita Wurst has revealed that she is HIV positive and has been receiving regular treatment for "several years".
The 29-year-old star, who won the song contest for Austria in 2014, said she had wanted to keep the information private, but a former boyfriend had "threatened to go public".
"I will not give anyone the right to frighten me and influence my life," she wrote on Instagram.
"Coming out is better than being outed by a third party."
Wurst revealed that regular treatment had suppressed the virus. Moreover, it could no longer be detected in her blood and could not be passed on.
"I hope to give others courage and to take another step against the stigmatization of people who, through their own behaviour or that of others, have become infected with HIV," the singer added.
Aids charity The Terrence Higgins Trust expressed dismay that Wurst had been obliged to reveal her diagnosis.
"The decision to talk openly about your HIV status should be a personal one and not taken away or ever, ever used as a threat," chief executive Ian Green said.
"Threatening to reveal someone's HIV status, under any circumstances, is entirely wrong. What other health condition would be used as blackmail against someone? And we know this isn't something which only happens to those in the public eye."
Green praised Wurst for handling the situation "with such dignity" and attempting to "tackle the abhorrent stigma" surrounding HIV and Aids.
Born Tom Neuwirth in Styria, Austria, Conchita became an international sensation when she won Eurovision in with Rise Like A Phoenix.
In February of this year, Conchita topped the bill at a concert from the London Palladium, accompanied by the 60-piece BBC Concert Orchestra, incorporating her own band and special guests BETSY and Mica Paris. It was broadcast on BBC Radio 2's Friday Night Is Music Night.