Australian actress Nicole Kidman and New Zealand-Australian musician Keith Urban.
AFP/File

An American model says she was having an affair with Keith Urban while he was engaged to Australian actress Nicole Kidman and has spoken of the country star's drug habit.

Amanda Wyatt, a 23-year-old part-time model who met Urban at a bar, said they never used protection during their relationship which began in 2004 and continued until May this year - the month before Urban and Kidman married.

The pair was also seen being intimate in October this year, around the time when Urban checked himself into the Betty Ford rehabilitation clinic to treat his drug addiction.

"I'm sorry if I hurt Nicole but I just want to tell the truth and move on," Ms Wyatt told Britain's The Mail on Sunday.

"I hope that she finds happiness with him but Keith is a deeply troubled man.

"I hope for her sake that he sorts himself out. She deserves better."

Wyatt said she continued to see Urban regularly even after finding out of his burgeoning romance with Kidman in mid-2005.

"I guess I knew he was seeing her but he was also seeing me," Wyatt said.

"He wasn't married so I still held out hope that they were just having some kind of publicity relationship.

"You have to understand, Keith was a star and I was a nobody, but even by his standards Nicole was a superstar."

Wyatt says their sexual relationship lasted long after he began seeing Kidman.

"When we made love he never used protection," Wyatt said.

"He told me that he liked that I didn't pressurise him to get married or have babies.

"I sometimes wonder if he said the same thing to Nicole.

"I never wanted to trap him.

"I tried not to fall in love with him but we were together throughout the whole time he was dating Nicole and engaged to her, right through 2005 and to around May 2006.

"Whenever he was in town we'd see each other two or three times a week.

"We'd drink and party and make love and (were) constantly on drugs."

Wyatt said Urban had been misleading his own family about his substance abuse.

"He drank constantly - his favourite was Crown Royal Reserve whisky - and he did drugs. Ecstasy, cocaine, pot - you name it," Wyatt said.

"He told me he'd been in rehab for cocaine and when his mother was there from Australia she was very protective of him. She kept telling me it was okay for him to drink but begged me not to let him do cocaine again. I didn't dare tell her the truth - that he was still doing it.

"Looking back, I rarely saw him sober. He'd work during the day but the bourbon would be flowing and, at night, he'd take ecstasy and coke. We partied constantly."

via www.theaustralian.news.com.au