Federal prosecutors on Tuesday indicted the Southern Poverty Law Center (SPLC) for fraud, alleging the civil rights group secretly used donor money to pay leaders and members of white supremacist and other extremist groups for inside information, the Justice Department said.

Acting Attorney General Todd Blanche said the Alabama-based nonprofit raised millions of dollars that it used for an informant program that prosecutors say directed as much as $3 million to sources embedded in hate groups like the Ku Klux Klan. The indictment alleges the SPLC used front organizations to move money through bank accounts without detection and hide the payments’ purposes.

The Justice Department is charging the SPLC with wire fraud, bank fraud and conspiracy to commit money laundering. The organization denies the allegations and said it would vigorously fight the case.