Oksana Grigorieva's Sister Suspected Of Leaking Mel Tapes

Oksana Grigorieva has long maintained that she is not the one who leaked the tapes of her incendiary conversations with Mel Gibson -- but now a source claims that it may actually have been Grigorieva's younger sister Natalie who was responsible.

"I suspect that if the authorities look at the sister, they'll find a wire transfer or a check to her from the website [that published the tapes]" a source told THR. "She and Oksana are very close."

But it's still possible that a judge could find Oksana guilty of extortion if it's found that Natalie brokered the deal with Radar for her sister.

Oksana and Mel continue to battle it out in court over custody of their daughter Lucia, 7 months.