R&B singer Usher - who now mentors teen sensation Justin Bieber - has opened up about his time as a ward of rap legend and music biz mogul P. Diddy.

Diddy - real name Sean Combs who at that time went under the moniker Puff Daddy - used to take a 14-year-old Usher to wild parties.

Usher explained:"Puffy's idea was to make me a bit rougher with more edge.

"But I'm not saying Puff was wrong. That first album wasn't my most successful but it launched the career I've enjoyed for 18 years since. It's helped me understand the importance of having a mentor when I'm working with Justin. You have to make music relevant for now."

CEO of LeFace Records, L.A. Reid also recently revealed that P. Diddy convinced him to keep the teenage Usher on the label when he had contemplated dropping the star.

He said:"I wanted to drop him. I wanted to be out of business with him. I broke his heart. I broke his mother's heart. It was a very tough period in both our lives.

"Then someone said to me, 'Don't be a fool. Don't sell your stock in Usher. He's still going to be a star. He's everything you thought he was the day you signed him'. And that person was [Diddy].

Watch the young Usher in the video for the 1997 hit 'You Make Me Wanna...' here: