Britney Spears receiving letters and packages from a stalker

Troubled pop princess Britney has been receiving letters and packages from a stalker, it has been claimed.

The Toxic star is said to have been so concerned by the disturbing mail, which reportedly included a letter detailing how to make bombs and another containing "threatening language and weird gibberish", she has handed all correspondence over to the FBI.

A source close to the singer told E!: "A lot of the things she was receiving were disturbing stalker kind of stuff. So, to be safe, her security team is turning it all over to the police and FBI."

While insiders claim the mail had been sent to Britney's various properties, LAPD spokesperson Ana Aguirre said no specific investigation had been launched yet.

She added: "We have been looking at allegations that have cropped up in the past couple of months."

An FBI spokesperson refused to comment on the allegations.