London's Metropolitan Police have confirmed that they have launched an investigation into disgraced actor Kevin Spacey over an alleged incident of sexual assault said to have taken place in 2008.

According to The Sun, an unnamed British actor claims he woke to find the Oscar-winning star performing a sex act on him after he had passed out in Spacey's home after being invited back for a drink.

The Met told Buzzfeed that the investigation stemmed from a complaint, who was 23 at the the time, submitted to City of London Police. "It is alleged a man assaulted another man in 2008 in Lambeth," a statement said. "Officers from the Child Abuse and Sexual Offences Command are investigating."

Spacey was not named, but sources have confirmed to Buzzfeed that he is at the centre of the investigation.

It is understood that the complainant had asked the House of Cards star, who was artistic director of the Old Vic Theatre between 2004 and 2015, to help with his career, The Sun reported.

News of the investigation follows several allegations against the House of Cards star, beginning with actor Anthony Rapp's claim that Spacey made a sexual advance on him following a party in 1986 when he was 14-years-old.

In response Spacey said he was "beyond horrified" to hear the claim but said he did not remember the incident. He added however that if it did happen as described, he was "deeply sorry".

Others have come forward since then, including filmmaker Tony Montana, who claims Spacey drunkenly grabbed his crotch in a Los Angeles bar and said "This designates ownership," before following him to a bathroom and then being escorted away by friends.

Roberto Cavazos, a Mexican actor, recalled being "squeezed" by Spacey in a "couple of unpleasant encounters" at the Old Vic bar. Spacey was artistic director at the famed Lambeth theatre from 2004 to 2015.

Another man, speaking to Vulture on condition of anonymity, says he had a sexual relationship with Spacey when he was 14 and the actor was 24. He also claims that on one occasion Spacey attempted to forcibly have sex with him despite his protests.

Following the initial allegation Netflix announced the end of prestige series House of Cards, in which Spacey starred as a corrupt politician. Netflix later shut down production on the show's impending sixth season "until further notice".

Last night (2 November) CNN published a report quoting eight people who worked on the show who described a pattern of sexual harassment and assault by Spacey.

"I have no doubt that this type of predatory behavior was routine for him and that my experience was one of many and that Kevin had few if any qualms about exploiting his status and position," said one unnamed production assistant.

"It was a toxic environment for young men who had to interact with him at all in the crew, cast, background actors."

Spacey has denied all allegations made against him.