Keith Urban opens up about his heartbreaking childhood.

Having lost his father to cancer last year, Keith Urban has opened up about the difficult and at times troubling relationship he and Robert shared.

“My dad was an alcoholic, and I grew up in an alcoholic’s house,” Keith told Rolling Stone magazine earlier this week.

The addiction – a streak that 48-year-old Keith also shares and has battled with over the years – was one that was all consuming, he says.

Urban performing earlier this year. Source: Instagram.

"My recollection is that he was a physical disciplinarian," the father-of-two says, adding that he can't remember Robert ever telling him he loved him while growing up.

But like many alcoholics, Keith believes that if he were here today, Robert's version of history would be told differently.

Keith Urban takes on Carpool Karaoke with wife Nicole Kidman. Post continues... 

"I don't think he was in denial," the American Idol judge says before explaining, "he genuinely had no recollection," adding that when issues were raised by Keith, his father would retort, "Hitting you? I never did that!"

Keith has spoken openly about his struggles with cocaine addiction. Having sought treatment throughout the years, he largely credits wife Nicole Kidman for his now long-running sobriety.

Now a father to Sunday Rose, 7, and Faith Margaret, 5, it's clear that with the help of Kidman, Keith has broken the destructive cycle and has wonderful relationships with his daughters.

Nicole Kidman and Keith Urban at the 2016 CMT Awards. Source: Instagram.

Despite Robert's alcoholism, Keith says that it was his father who is responsible for much of his success as a musician, saying that the need to strive for his father's approval was what drove him.

Now 25 years into his country music career, Urban has released ten solo albums and amassed a whopping 19 number one hit singles and 32 music awards. That's something any parent would surely be proud of.

Robert was 73 years old when he passed away last year.