US gossip site The Smoking Gun reports that the fake lawsuit was in fact filed by convicted felon Jonathan Lee Riches.
Riches filed papers posing as Christopher Federline, in which he sought a restraining order against Britney after she "stole" his credit card.
He also alleged that she blackmailed him by saying she would reveal that he was the "true father" of seven-year-old Sean Preston if he went to the police.
According to the Daily Mail, Riches also recently pretended to be the uncle of Newtown gunman Adam Lanza. He has reportedly since been arrested for violating his probation.
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