Legal papers reportedly filed against Britney Spears by her former brother-in-law have been exposed as part of a hoax contrived by a recently released felon.

Members of Christopher Federline's family are now investigating the matter, according to Us Weekly magazine editors, who obtained the documents on Wednesday (26Dec12).

Their concerns were raised as the papers are full of private information about the brother of Spears' ex-husband Kevin Federline, and features a very accurate signature forge.

In the legal documents, the plaintiff claimed that he was the "true father" of Spears' oldest son, Sean Preston, and he filed for a restraining order against the pop star to stop her from exposing the details.

Bosses at website TheSmokingGun.com have confirmed the papers are fake and the work of Jonathan Lee Riches, a conman with a long history of faking identities to concoct elaborate hoaxes .

Riches recently posed as Sandy Hook Elementary School shooter Adam Lanza's uncle, offering interviews to the media gathered in Newtown, Connecticut, where the massacre took place earlier this month (Dec12).

He was later arrested for violating federal probation as he is currently serving five-years probation for conspiracy and wire fraud.

TheSmokingGun reports Riches also reportedly filed "hundreds" of fake lawsuits from prison.