Justin Bieber's fans have caused "pandemonium" at a London hotel where he's staying, with the establishment receiving over 2,000 calls.

The Canadian sensation is currently in Britain's capital city to promote his new album Believe. Justin has famously over-zealous fans and his UK followers have been capitalising on the fact that he is in close proximity.

Some have been trying to get through to his suite at the Royal Garden Hotel by pretending to be friends and relatives - with one even claiming to be Justin's personal stripper.

"Justin's fan base are relentless they will do anything to get near him. The phones in the hotel haven't stopped ringing since he arrived," a source told British newspaper The Sun.

"Staff knew there would be pandemonium but not to this extent."

Justin didn't help matters by firing up his female fans at the hotel window when he lifted up his top to reveal his toned six-pack.

Meanwhile, Justin was reportedly rude at a screening of his new album at London's Supperclub venue. When the star was offered a seat as he arrived on stage he retorted: "No, I want to introduce my song," before telling manager Scott 'Scooter' Braun, to play Believe on a MacBook.

According to British newspaper The Mirror, the teenage sensation then snapped: "It sounds so bad!"

Justin was asked about how he felt being compared to Justin Timberlake on his newest single Boyfriend.

"I sound nothing like Justin Timberlake," he said, before introducing his song As Long As You Love Me.

"It's a really, really, really good song. But it's probably gonna sound like c**p through these speakers."