Metropolitan police say they are looking into allegation that Hollywood star assaulted man in Lambeth, London

British police are investigating Kevin Spacey over a second sexual assault allegation, the Guardian understands.

The Metropolitan police said on Wednesday they were looking into the fresh claims against the Hollywood actor, having opened an investigation into similar allegations against him earlier this month.

According to the latest allegations, Spacey sexually assaulted a man, identified only as Victim 2, in 2005. The claims were referred to the Met by City of London police last Friday, Scotland Yard said.

The earlier claims related to an alleged sexual assault perpetrated against a man identified as Victim 1 in 2008 and were referred by the same force. Each was allegedly committed in the Lambeth area of south London and, in each case, police refused to name the suspect.

However, officers did confirm that each was made against the same man and he is understood to be Spacey. “Officers from the child abuse and sexual offences command are investigating,” the Met said on Wednesday.

Spacey has faced a series of accusations of sexual misconduct in the US and the UK. Last week, the Old Vic theatre, where he was artistic director from 2003 to 2015, said it had been contacted by 56 people with 20 individual allegations of inappropriate conduct, including some allegedly perpetrated against former staff.

It said 14 were so serious it had advised the complainants to contact the police, and apologised for failing to ensure there was an environment in which people felt they could come forward.

“The Old Vic apologises wholeheartedly to the people who told us that they have been affected. We’ve learned that it is not enough to have the right process in place. Everyone needs to feel able to speak out no matter who they are,” the theatre’s executive director, Kate Varah, said.

“That apology really goes to the people who feel they were affected by this but what is also important to understand is there is a new way forward for this organisation.”

The concerns about Spacey’s behaviour came to wider public attention after the revelations about Harvey Weinstein. The actor Anthony Rapp told BuzzFeed that when he was aged 14, Spacey, then 26, had tried to “seduce” him.

Spacey said: “I honestly do not remember the encounter, it would have been over 30 years ago. But if I did behave then as he describes, I owe him the sincerest apology.”