Telephone lines at Justin Bieber's London hotel have been jammed by more than 2,000 calls from fans.

Teenagers desperate to speak to the 'Boyfriend' singer - who arrived in London on Monday - have been trying to get through to his suite at the Royal Garden Hotel by pretending to be friends, relatives and even his personal stripper.

A source said: "Justin's fanbase are relentless -- they will do anything to get near him.

"The phones in the hotel haven't stopped ringing since he arrived.

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

According to The Sun newspaper, the cheeky 18-year-old got fans fired up by flashing his six-pack from the hotel window before sneaking off for a 99p McFlurry from McDonald's.

Meanwhile, Justin - who recently treated girlfriend Selena Gomez to a romantic picnic in Los Angeles - believes the way to a girl's heart is through her stomach.

He said: "Girls would rather have love than gifts.

"What is a gift? It's just something from a store. Girls love something that is done for them from the heart, rather than gifts. Girls love picnics."