The FBI says it has reason to believe U.S. Rep. Bob Brady unlawfully concealed a $90,000 payment made by the Philadelphia Democrat’s campaign to get an opponent to quit a 2012 primary race.

According to federal court documents unsealed Monday, the FBI requested a search warrant and has obtained one CD of data from an email account belonging to Brady.

Brady has not been charged with a crime, but the filings confirm the powerful congressman is under investigation for the payment. His attorney says they’ve already provided the emails to authorities and that Brady has done nothing wrong.

The primary opponent and a former aide have pleaded guilty to concealing the payment. Two political consultants also have been charged in the case.