Justin Bieber is seen telling a racist joke in a controversial video.

The 'Boyfriend' hitmaker appears in the clip, which has been posted online by the The Sun on Sunday newspaper, joking with friends and uses the 'N word' five times after asking them: ''Why are black people afraid of chainsaws?''

One friend repeatedly warns the pop star: ''Don't even say it. Don't say it,'' but he laughs and decides to deliver the punch-line, saying: ''Run n****r, n****r, n****r, n****r, n***r.''

A female friend, who cannot be seen, then tells him: ''You could say motorcycle too'', before making revving engine noises.

The 20-year-old singer is thought to have been 17 when the moment was captured on camera during filming for his first documentary 'Never Say Never' in 2011.

According to The Sun on Sunday newspaper, Justin and his management have known about the video for a while and tried to pay for it to be kept out of the public eye.

A source said: ''This video is Justin Bieber and his camp's worst nightmare. Even after the year he's had - when he's never been far from controversy - this tops it.''

Justin was arrested in Miami in January and charged with driving under the influence (DUI), resisting arrest and possessing an invalid driver's license and he was later accused of attempted robbery after a woman claimed he grabbed her mobile phone while she was trying to take a photograph of him.

The new video is likely to anger a number of African-American artists, who have helped him to become a global superstar and supported him throughout his career, including Usher, Will.i.am and Will Smith.

The source continued: ''Justin has been taken under the wing by some of the best in the industry and they won't stand by him after this.

''This will be a real kick in the teeth - showing his true colours on film.

''He's made millions from working with musicians from all ethnic backgrounds. Having this attributed to him will do him no favours in the future.

''This could be the end of the road for him if artists refuse to work with him based on this. And it sets a seriously bad example to his impressionable young fans.''