Bill Cosby -- The LAPD Wants Answers ... From the Man Himself

The LAPD wants to know if a 40-year-old sexual assault claim against Bill Cosby is legit -- and they want it from the horse's mouth.

Law enforcement sources tell TMZ ... they will contact Cosby ASAP to try getting him on the record. And the detectives who will do the interview -- assuming Cosby consents -- are elite. The case has been assigned to the Robbery-Homicide Division.

As we previously reported ... the LAPD is already on the hunt for documents and interviews from people at the Playboy Mansion to determine if Cosby was even there when the alleged incident took place.

Judy Huth filed a police report Friday ... saying she was 15 when Cosby got her drunk in 1974 ... then sexually assaulted her at the famous mansion.

Cosby has already said Huth is a liar in court docs ... so we're guessing his interview will sound similar.

BTW ... the chances of Cosby talking to cops are way less than slim. He has nothing to gain ... the statute of limitations has long run on the alleged crime.