(REUTERS) - Oscar-winning actor Kevin Spacey has apologised to fellow actor Anthony Rapp who said Spacey made a sexual advance to him in 1986 when Rapp was 14 years old.

Spacey said in a post on Twitter on Sunday that he was"beyond horrified" to hear Rapp's story of the encounter, which he said he did not remember. He wrote that he owed Rapp a "sincere apology" for what he said would have been "deeply inappropriate drunken behaviour."

In an interview with BuzzFeed, Rapp described attending a party hosted by Spacey in which the actor picked him up, brought him to a bed and lay down on top of him after other guests left.

Rapp, who said he had the impression Spacey was drunk, pushed him away and left.

Spacey, 58, who has won Oscars for The Usual Suspects and American Beauty, also said that Rapp's story "had encouraged me to address other things in my life."

"I have loved and had romantic encounters with men throughout my life, and I now choose to live life as a gay man," Spacey wrote. "I want to deal with this honestly and openly," he said,"and that starts with me examining my own behaviour."

The actor for years had declined to publicly discuss his sexuality.

Rapp, who went on to star in the Broadway musical Rent, was starting his career on Broadway at the time of the incident.

"He was trying to seduce me," Rapp told BuzzFeed of the encounter with Spacey. "I don't know if I would have used that language. But I was aware that he was trying to get with me sexually."

Rapp said on Twitter overnight that he had decided to come forward and tell his story, "standing on the shoulders of the many courageous women and men who have been speaking out ... to shine a light and hopefully make a difference, as they have done for me."

Everything he wanted to say about the experience had been covered in the interview, Rapp tweeted, adding that he had no further comment to make.

Spacey, a Tony Award winner for Lost in Yonkers, stars in the Netflix political drama House of Cards. He was also artistic director of London's Old Vic theater company for 10 years.

Some on social media were infuriated by Spacey's conflation of the incident and his coming out as gay. Actor and writer Louise Brealey said on Twitter that "trying to hide behind coming out and offering drunkenness as an excuse for jumping on a child shows (Spacey's) breathtaking arrogance."

The psychology of living in the closet was dark, cruel and self-punishing, wrote Vanity Fair film critic Richard Lawson. "That Spacey has dwelt in that for years is sad. But 14 is 14," Lawson tweeted.

"The distance we've had to walk to get away from the notion that we're all pedophiles is significant. ... How dare you implicate us all in this."

Hollywood and some top US companies have been rocked in recent weeks by allegations from scores of women that executives had sexually harassed them.

US movie mogul Harvey Weinstein has been accused by numerous women of having sexually harassed or assaulted them in incidents dating back to the 1980s, including some who said they were raped.

Weinstein denies having non-consensual sex with anyone. He has since been fired as chief executive of The Weinstein Company, which he co-founded and has which been one of Hollywood's most influential forces since its launch in October 2005.