Gibson's ex in extortion probe

Sheriff’s detectives in Los Angeles are investigating extortion allegations against Mel Gibson’s ex-girlfriend, it was revealed today.

Sheriff’s spokesman Steve Whitmore said the agency is looking into whether Russian singer Oksana Grigorieva may have tried to extort the Academy Award-winner. He refused to give further details.

Earlier this month detectives interviewed Ms Grigorieva after she claimed the actor abused her during an incident in January.

A spokesman for Ms Grigorieva declined to comment.

Gibson and Ms Grigorieva are locked in a bitter custody dispute over their baby daughter.

No arrests have been made, and neither has been charged with any crimes.