Police in the US have begun an investigation after a man filed a report alleging he was assaulted by singer Justin Bieber at a hotel in Cleveland, Ohio in June.  

Las Vegas man Rodney Cannon has alleged that he was assaulted by the 22-year-old star and his bodyguards on June 8 after a Cleveland Cavaliers basketball match.

In the report he filed with Cleveland Police this week, Cannon said he had accused the singer of taking his sunglasses at the Western Hotel and during the alleged incident Bieber became "angry" before allegedly assaulting him. 

Justin Bieber is the subject of an investigation by US Police following an alleged assault

"(The alleged) victim stated he believed he was punched three times during the whole incident by Justin Bieber," the report states.

"(The alleged) victim also stated that he believes he was also punched by Justin Bieber's bodyguards a couple of times.

"(The alleged) victim stated that he took (Bieber) down to restrain him.... He believes that (Bieber's) bodyguard punched him while he was restraining (Bieber)."

No charges have been made in relation to the alleged incident

Cannon said he went to hospital in his home state of Nevada following the alleged incident with an "acute head injury and a possible concussion".

A spokesman for Cleveland Police said there had been no charges in connection with the alleged incident. Bieber's representatives have not commented.