A sexual assault charge against Kevin Spacey is being considered by prosecutors in Los Angeles.
The police investigation in California is the first known case outside of the United Kingdom.
Los Angeles County Sheriff's Department spokeswoman Nicole Nishida said that the force's "special victims bureau began an investigation into allegations of a sexual assault involving Mr Kevin Spacey on December 11, 2017".
"The events were reported to have taken place in October of 1992 in West Hollywood involving a male adult," she added.
Scotland Yard has been investigating allegations of sexual assault on three men in London, spanning from 2005 to 2008.
Actor Anthony Rapp was the first to make an allegation, claiming he was 14 when a 26-year-old Spacey made a sexual advance in 1986.
Spacey, said he did not remember the encounter but apologised for any "inappropriate drunken behaviour".
The Old Vic theatre in London, where Spacey was artistic director from 2004 to 2015, received complaints from 20 people of inappropriate behaviour by the actor.
Spacey was then sacked by Netflix's House Of Cards and Sir Ridley Scott replaced him in the completed film All The Money In The World in re-shoots costing millions.
A spokeswoman for Spacey's legal team declined to comment on the latest investigation.