By Agence France-Presse
"I can confirm our office received a case" involving Spacey, said Greg Risling, a spokesman for Los Angeles County District Attorney Jackie Lacey told AFP.
But according to celebrity news site TMZ, the case will likely be rejected because it involves an allegation from the 1990s and is outside the statute of limitations.
The 58-year-old is also being investigated over similar allegations in London and Nantucket, an island off the coast of Massachusetts.
Two-time Oscar winner Spacey has disappeared from public life. Considered one of the pre-eminent actors of his generation, he was dropped from Ridley Scott's "All The Money In The World" and expunged from the Netflix hit show "House of Cards."
Case files on Harvey Weinstein, the Hollywood producer whose downfall sparked the #MeToo movement against powerful male harassers, and martial arts star Steven Seagal "remain under review," said Risling.