The shocking split between long-time celebrity love birds Nicole Kidman and Keith Urban could take another surprise twist due to a bizarre legal quirk.

When the megastars got hitched back in 2006, they signed a prenuptial agreement to protect their assets, and while the pair have not officially announced a divorce yet, all signs point to the relationship heading down that path.

If that were to be the outcome then it could trigger the unusual ‘cocaine’ clause written in their marital contract — making Urban, 57, an even richer man.

The cocaine clause means if Urban stayed clean from drug and alcohol, the four time Grammy Award winner will receive more than $900,000 from Kidman, 58, for every year they were married, adding up to more than $17 million.

Despite being vocal about his sobriety, it was a vastly different story for the Somebody Like You singer when him and Kidman first married.

The highly decorated country music star was struggling with his addiction to drugs and alcohol and was forced into rehab just three months after he married the Eyes Wide Shut actress.

Urban has publicly credited his wife with helping him overcome a crippling addiction that he had not received any help for prior to meeting her.

“That’s the point right there where she really should’ve just walked,” Urban told Oprah Winfrey in 2010.

“I’m just so glad she didn’t, and she made a decision to turn around and initiate ultimately this intervention, and it was done in such a way that the love in that room at that moment was just right. I was like, ‘Put the cuffs on, let’s go.’”

It’s understood his addiction prompted Kidman to add the cocaine clause into the prenup.

The Australian icons have been living apart since early summer according to TMZ, with the root of their marriage breakdown still unclear.

Sources close to the pair say that Kidman has been fighting tooth and nail to save their relationship, but Urban appears adamant on ending their near two decade relationship.

They share two children together, and the six time Golden Globe winner has another two adopted children from her past marriage with actor Tom Cruise.