LAPD Investigating Mel Gibson’s Ex Oksana for Extortion

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Did Oksana Grigorieva attempt to blackmail Mel Gibson by threatening to leak their infamous phone tapes? The Los Angeles County Sheriff's Department aims to find out.

"Extortion allegations have been brought to our attention and we are certainly going to be looking at that," Steve Whitmore of the sheriff's department confirmed to TMZ on Wednesday.

Grigorieva's attorney Stephen Jaffe later denied the allegations, saying that his client "has repeatedly stated that there is no credible evidence whatsoever of extortion by her, and she stands steadfastly by that statement."

On Tuesday, Gibson's attorney argued to police that her team had solid proof that Grigorieva, 40, tried to extort ex Gibson, 54; the lawyer also charges that Grigorieva lied to authorities.

Locked in a vicious custody battle over their infant daughter Lucia, Gibson and Grigorieva have been swapping accusations back and forth for weeks. Over the weekend, a rep for Grigorieva denied that the Russian musician had leaked the shocking phone conversations posted online over the past couple weeks.

In the sixth tape, posted on Tuesday, Grigorieva accuses the actor/director of hitting her and their daughter. Gibson explodes and retorts, "I want my child, and no one will believe you."

A disturbing photo of a battered Grigorieva — reportedly after a Jan. 7 fight with Gibson — surfaced online Friday.

A rep for the dentist who examined Grigorieva the day after the alleged incident said, "Based on Dr. Shelden's observations and his experience, Oksana sustained injuries from being struck twice, once in the side of the head and once in the mouth."

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