A man who won one of the largest lottery payments in U.S. history has filed a federal lawsuit against the mother of his child in an attempt to keep his identity concealed.

The man won a $1.35 billion Mega Millions jackpot earlier this year after purchasing a lottery ticket at a gas station in Lebanon, Maine. He has sued his child’s mother in U.S. District Court in Portland with a complaint that she violated a nondisclosure agreement by “directly or indirectly disclosing protected subject matter” about his winnings, court papers state.

The court papers state that the defendant in the case disclosed the information to the winner’s father and stepmother. Both the winner and the defendant in the case are identified only by pseudonyms.