Police refused to name the suspect in the case which they stated was the same individual accused in relation to a separate assault alleged to have taken place in 2008 in the same area.
A two-time Academy Award victor, Spacey was artistic director of London's Old Vic Theatre between 2004 and 2015.More news: Breezy winds and chilly temperatures to continue heading into Thanksgiving day!
"The allegations are of sexual assaults against a man, victim two, in 2005 in Lambeth".
"On Wednesday, November 1, City of London Police referred an allegation of sexual assault to the Metropolitan Police Service", they said.
A spokesperson did not identify the alleged attacker but confirmed the latest allegation, made on Friday, concerned the same man.More news: Harrison Ford lends hand to woman in vehicle accident
It opened the investigation following a stream of allegations against the actor, including testimony from Mexican actor Rob Cavazos, who worked with Spacey at the Old Vic.
The Old Vic said it received the claims of inappropriate behaviour in recent weeks, although the alleged incidents were said to have taken place from 1995 to 2013. These allegations have been a shock and a disturbing surprise to many of us. The Old Vic said a "cult of personality" around Spacey had discouraged people from speaking out.
Alleged victim, Daniel Beal said that Spacey showed him his penis in public when he was 19, before giving him his £5,000 watch to buy his silence.More news: Trump Tagged again DPRK as Terrorist Country
Netflix and Sony Pictures have cut ties with the star, firing him from House Of Cards and replacing him in upcoming film All the Money in the World. He has denied allegations of assault, but said he is now seeking "evaluation and treatment" of his behavior. Neither Kevin Spacey nor his representatives have responded at press time.