British singer Robbie Williams revealed he'd buy and take drugs with her daughter if she wanted to when she grows up.

"If unfortunately that does happen, I'll know what to do. Which is make sure she's got the best drugs possible - and take them with her," he said.

Williams, 39, is no stranger to drug and alcohol addiction in the past but has since become sober after checking into rehab back in 2007.

He and his wife, Ayda Field, welcomed their baby daughter Theodora "Teddy" Rose in September last year.

The ex-Take That star is willing to sacrifice his sobriety when the time comes that Teddy wants to experiment.

"I doubt she'll be like me. Touch wood, and follow that with a lot of love and a lot of luck, she won't go there or have to go there." he told the new Australian magazine, Sunday Style.

He has penned a song for his daughter inspired by his dark experiences with substance abuse. The song goes "Sit down, close the door I think it's time you knew the score, why you feel weird. One day you'll be told about, how Daddy let his demons out, yeah he makes them scream and shout."

"So what better when you're old enough, and you're out on your own and stuff, if you start losing hold of love it's because..."

"Your uncle sells drugs, your cousin is a cutter, your grandma is a fluffer, your grandad's in the gutter, your mother is a nutter, you're a mad motherf**ker, " the pop star shared.