I choose now to live as a gay man, Kevin Spacey said in his apology to US actor Anthony Rapp, who alleged that the star had made unwanted sexual advances on him. File picture: Evan Agostini/Invision/AP

Washington - Kevin Spacey apologised to US actor Anthony Rapp late Sunday, after he alleged that the Hollywood star made unwanted sexual advances on him when he was a teenager.

In an article published by BuzzFeed, Rapp alleged that Spacey invited him over to his apartment for a party in 1986 and at the end of the night, picked Rapp up, placed him on his bed and climbed on top of him, making a sexual advance.

Spacey, 58, responded to the allegations on Twitter saying he "honestly" did not remember the incident.

"But if I did behave then as he describes, I owe him the sincerest apology for what would have been deeply inappropriate drunken behaviour," Spacey wrote.

"As those closest to me know, in my life I have had relationships with both men and women. I have loved and had romantic encounters with men throughout my life, and I choose now to live as a gay man," Spacey added.

In 2000, Spacey denied in an interview that he was gay, following an article in Esquire magazine in 1997 insinuating that he was.