Justin Bieber is no longer facing an assault charge over an incident involving a limousine driver.

Prosecutors have said they have dropped the charge against the Baby singer.

It stemmed from an early morning incident late last December, when Justin and five other people were picked up by a limousine from a nightclub in Toronto, Canada.

Police alleged the Canadian pop star, 20, hit the limo driver several times in the back of the head.

Prosecutors said the charge was withdrawn because there was no reasonable prospect of conviction.

"It was the right decision based on the evidence and we're pleased," said Brian Greenspan, Bieber's lawyer. "It's our belief that no one assaulted the driver."

Bieber is relieved and ready to move on with his career with one less diversion, Greenspan said.

It was just one episode in the star's ongoing troubles with the law.

Justin is due in an Ontario court on September 29 to fight new charges. Greenspan said last week that the star had been arrested on August 29 for dangerous driving and assault following a collision between a minivan and an ATV that led to a physical altercation with a photographer.

Greenspan said Justin was near his hometown of Stratford, Ontario, on a "peaceful retreat" with actress and singer Selena Gomez - his on-off girlfriend - that "was unfortunately disrupted by the unwelcome presence of the paparazzi".

Police said there were no injuries as a result of the collision, but could not say whether there were any injuries from the altercation.

Bieber had earlier been photographed on an ATV vehicle with Gomez, his on-and-off again girlfriend.

Just days before the Ontario incident, Bieber's car was hit from behind by a vehicle driven by a photographer in Hollywood. Bieber later tweeted: "I don't have a problem with paparazzi but when they act recklessly they put us all in danger."

Last month, Justin pleaded guilty to misdemeanour charges of careless driving and resisting arrest seven months after his arrest in Miami Beach for what police initially alleged was an illegal street drag race. In a plea bargain, he agreed to an anger management course, a fine and a charitable contribution.