Justin Bieber has been accused of assault.

The 18-year-old pop star was allegedly involved in a physical altercation with a photographer at The Commons mall in Calabasas, California - where he has just purchased a $6.5 million mansion - after a paparazzo attempted to take pictures of the "Boyfriend" singer and his girlfriend Selena Gomez.

Following the incident, the photographer called the police before he was taken to hospital complaining of chest pains, but he was discharged shortly afterwards, TMZ.com reports.

When police arrived at the scene Justin and Selena had already left the shopping center - where they had gone to watch a film - but the officials are hoping to speak to the "Never Say Never" hitmaker and any other witnesses about the altercation after the snapper filed a report to the police naming Justin as the culprit. Witnesses, however, have claimed the paparazzo was blocking Justin's car in as he was trying to leave the shopping center, and the singer is then said to have got out of the vehicle to ask him to move away but he didn't so a scuffle broke out.

According to the gossip website, several witnesses also saw a lawyer walk up to the photographer and advise him to call for an ambulance and file a police report following the incident.