Keith Urban's 'cocaine clause' could make him millions from Nicole Kidman divorce

Keith Urban could stand to gain millions in his divorce from Nicole Kidman thanks to a 'cocaine clause' included in their prenup.

The country music star, 57, might be quids in when his marriage to the Babygirl actress is formally dissolved, as he's held up his end of the bargain during their 19-year union.

The pair have a lot of assets to divide when their divorce eventually goes through, as they reportedly amassed a $500 million fortune together during their relationship.

Urban and Kidman have also got an enviable property portfolio and reportedly own 11 luxury pads together across the US and Australia.

The father-of-two, from New Zealand, is said to have moved out of the family home in Nashville and into another nearby property in wake of their split.

Reports claim that he and Kidman have lived apart since the start of summer.

Urban might be eyeing up a lavish pad to put down new roots in soon though, as he's apparently set to receive quite the windfall in the divorce.

The couple, pictured in 2006, were married for 19 years ( Kevin Mazur/WireImage)

The 'Days Go By' singer could pocket more than $17million from Kidman thanks to a so-called 'cocaine clause' that was reportedly included in their prenuptial agreement.

Before they walked down the aisle and said their 'I do's' in June 2006 at a ceremony in Sydney, the Aussie A-listers agreed to abide by a range of terms in the event of their relationship ending.

According to the New Zealand Herald, the legal document 'includes multiple clauses you wouldn’t find in a normal prenup' - including one relating to Urban sticking to his sobriety.

Prior to their wedding nearly two decades ago, the Grammy winner was grappling with drug addiction and alcoholism.

And just four months into their marriage, Kidman was forced to stage an intervention for her new husband, which Urban later described as a pivotal moment in turning his life around.

Earlier this year during an appearance on The Zane Lowe Show, he said of this time in his life: "All through the years of drinking and doing drugs and all the rest of it, I always had this very specific voice inside of me that goes, 'One day, you're gonna come to a crossroads or a fork in the road, and it'll be the final one'.

"I knew that was it," he said in reference to marrying Kidman. "I'm like, ‘Oh, this is that fork in the road'. You're either gonna choose to get out of this s**t, or you're never gonna get out of it."

Urban could stand to gain millions thanks to the 'cocaine clause' in their prenup, according to reports (John Shearer/Getty Images for ACM)

Urban previously told Rolling Stone that his issues with drugs and alcohol got out of hand after he moved from Australia to Nashville, while trying to crack the country music scene in the States.

"When I was onstage, I felt good, but if I was not onstage, I was very, very insecure," he said. "I felt like I didn’t have much of anything to offer. I was just an alien."

Urban went on to explain that a bad breakup prior to his relationship with Kidman only made matters worse, adding: "I stepped up my drinking. I started doing more drugs. Yeah, man. The whole back end of the Nineties were just awful."

He had a handful of unsuccessful stints in rehab but managed to get back on the straight and narrow with the help of his wife Kidman.

And as Urban has managed to maintain his sobriety over the last 19 years, he could be in for a huge payday.

Reports claim that a 'cocaine clause' was included in his and Kidman's prenup, which stated that he would receive a financial reward if he steered clear of booze and substances.

According to various outlets including Radar Online, it was reportedly agreed that Urban would earn $900,000 for every year of marriage he remained teetotal.