The justice department on Wednesday arrested a leading expert on far-right extremism, charging her with financial crimes as part of the government’s ongoing case against the Southern Poverty Law Center (SPLC).

Federal prosecutors charged Heidi Beirich, who formerly served as the group’s chief financial officer, with conspiracy to commit wire fraud, conspiracy to submit false statements to a federally insured bank, and conspiracy to commit concealment money laundering.

The justice department charged the SPLC in April over a now-ended program in which it paid informants to infiltrate white supremacist groups. The government said the civil rights organization committed financial crimes by laundering money through bank accounts set up on behalf of fictitious entities to protect the identities of their informants. The government says the SPLC deceived donors into thinking they were combatting extremism, when they were actually supporting it. The organization has strongly denied that accusation and says the charges are politically motivated. Experts have raised questions about the charges.

The indictment alleges Beirich was in a romantic relationship with one of the informants and that $140,000 of donor money made its way into a joint bank account they had.

Beirich now is the chief strategy officer and co-founder of the Global Project Against Hate and Extremism and is often sought out as an expert on far-right groups. She submitted testimony to the House committee that investigated the January 6 attack on the capitol about the extremism of the Proud Boys.

“A free and fair society does not use the justice system to silence its political opponents. Heidi Beirich has dedicated her life to fighting hate groups and extremist movements like the KKK, neo-Nazis, and other white supremacists,” her lawyer, Michael Proctor, said in a statement. “She has combatted these hateful, ugly, and un-American extremists and their repeated uses of violence and intimidation in order to promote a fairer, safer, and more just America. Her decades-long record of success dismantling hate groups – and the resulting threats to her life – speak volumes. For this, she has been indicted.”

Without ruling on the merits of the case, a federal judge in Alabama allowed the case to proceed last week, rejecting an argument from the SPLC that the case should be dismissed because it was a vindictive prosecution.