Usher wants "nothing to do with Justin Bieber's private parts".

The 'Yeah!' hitmaker - who helped launch the Canadian pop star's career with his manager Scooter Braun - said: "He does have a brain of his own. He listens he has a mind of his own. What he chose to do with his penis is his prerogative you know what I'm saying.

"He's managing that aspect of his life. I have nothing to do with Justin Bieber's private parts."

Meanwhile, the R&B superstar admits that while he always gives his protege his opinion he doesn't feel he has to be his life mentor because Justin is so young and he won't judge him on his past mistakes.

He told Howard Stern on his SiriusXM radio show: "I mean, as a mentor, he's accepted my opinion, I give my perspective. He's like a child to me so I don't necessarily feel like his business [coach].

"I feel like I'm talking to someone who has hardships. Like, if you child ever has difficulties ... anyone listening understands nobody's perfect."

The 22-year-old hunk was holidaying in Bora Bora in 2015 when the intimate pictures were taken and he worried his manhood would look less-than-impressive in the pictures.

He said: "I was scared. I first saw the one with the black bar over it. I was like, 'Oh, my God. I just got out of the water. Shrinkage is real.'"

However, it seems he had nothing to worry about.

He added: "No, no. That's as big as she gets."