Last week we told you about a mystery brunette seen hanging around the set of Mel Gibson’s new movie. Sources say the woman is Gibson’s mistress and that his marriage to wife Robyn is just about over. Mel and Robyn are one of Hollywood’s longest lasting couples, but insiders say she’s had enough of Mel and his destructive behavior-and the mistress is the last straw. However, don’t expect Robyn to go quietly. According to the latest issue of The National Enquirer, she’s looking to take a significant chunk of Mel’s nearly billion-dollar fortune with her when she goes.

Mel Gibson is facing Hollywood’s most costly divorce battle ever - a vicious battle over his whopping $900 million fortune!

Shocking new photographs of the rough-and-tumble Oscar winner with a sexy young Russian singer could be the final straw for the actor’s long-suffering wife Robyn, sources told The Enquirer.

The exotic beauty - a leggy 28-year-old brunette named Oksana - was first spotted with Gibson, 52, in September. She popped up again on the set of his latest movie a few weeks later - and for Robyn it will be the final nail in the couple’s turbulent 28-year marriage, insiders say.

“Robyn has had enough,” a close family friend told The Enquirer. “She’s been to hell and back with Mel over the years. The drinking, the cheating, the temper tantrums. The last time Robyn took him back she told him, ‘This is your last chance. If you embarrass me again, we’re done.’ And now she intends to keep her word.”

When asked about an impending divorce, Gibson’s spokesman told The Enquirer: “I have no reason to believe that there are problems in Mel’s marriage.”

[From The National Enquirer print version, Dec. 1, 2008]

Wow, what an affirmative denial by Mel’s PR guy. Doesn’t it just make you think everything’s fine? This could be a disaster for Gibson, who likes to tout himself as a devout Traditionalist Catholic - a religion where divorce is grounds for being excommunicated. He famously said this about his wife: “My wife is a saint. She’s a much better person than I am. Honestly. She’s, like, Episcopalian, Church of England. She prays, she believes in God, she knows Jesus, she believes in that stuff. And it’s just not fair if she doesn’t make it [to heaven], she’s better than I am. But that is a pronouncement from the chair. I go with it.”

Well, it looks like he’ll be “going with it” right to divorce court. I would be very surprised if Mel and Robyn have a prenup. She’s been with him for 28 years- before he got rich and famous - and they have seven children together. If the reports of a mistress are true, I don’t blame her one bit for going for the jugular. Half of $900 million can buy you a very well-appointed new life as a divorcee.

Picture note by JayBird: Here’s Mel Gibson at the premiere of American Gangster on October 29, 2007. Images thanks to PR Photos.