WASHINGTON (AP) — The Southern Poverty Law Center was indicted Tuesday on federal fraud charges alleging it improperly raised millions of dollars to pay informants to infiltrate the Ku Klux Klan and other extremist groups, acting Attorney General Todd Blanche said.

READ MORE: Southern Poverty Law Center says it faces a DOJ criminal probe over paid informants

The Justice Department alleges the civil rights group defrauded donors by using their money to fund the very extremism it claimed to be fighting, with payments of at least $3 million between 2014 and 2023 to people affiliated with the Ku Klux Klan, the United Klans of America, the National Socialist Party of America and other extremist groups.

"The SPLC was not dismantling these groups. It was instead manufacturing the extremism it purports to oppose by paying sources to stoke racial hatred," Blanche said.

The civil rights group faces charges including wire fraud, bank fraud and conspiracy to commit money laundering in the case brought by the Justice Department in Alabama, where the organization is based.

The indictment came shortly after SPLC revealed the existence of a criminal investigation into its program to pay informants to infiltrate extremist groups and gather information on their activities. The group said the program was used to monitor threats of violence and the information was often shared with local and federal law enforcement.

SPLC CEO Bryan Fair said the organization "will vigorously defend ourselves, our staff, and our work."

Blanche said the money was passed from the center through two different bank accounts before being loaded onto prepaid cards to give to the members of the extremist groups, which also included the National Socialist Movement and the Aryan Nations-affiliated Sadistic Souls Motorcycle Club. The group never disclosed to donors details of the informant program, he said.

"They're required to under the laws associated with a nonprofit to have certain transparency and honesty in what they're telling donors they're going to spend money on and what their mission statement is and what they're raising money doing," he said.

The indictment includes details on at least nine unnamed informants were paid by the SPLC through a secret program that prosecutors say began in the 1980s. Within the SPLC, they were known as field sources or "the Fs," according to the indictment. One informant was paid more than $1 million between 2014 and 2023 while affiliated with the neo-Nazi National Alliance, the indictment said. Another was the Imperial Wizard of the United Klans of America.

The SPLC said the program was kept quiet to protect the safety of informants.

"When we began working with informants, we were living in the shadow of the height of the Civil Rights Movement, which had seen bombings at churches, state-sponsored violence against demonstrators, and the murders of activists that went unanswered by the justice system," Fair said. "There is no question that what we learned from informants saved lives."

The center has been targeted by Republicans

The SPLC, which is based in Montgomery, Alabama, was founded in 1971 and used civil litigation to fight white supremacist groups. The nonprofit has become a popular target among Republicans who see it as overly leftist and partisan.

The investigation could add to concerns that Trump's Republican administration is using the Justice Department to go after conservative opponents and his critics. It follows a number of other investigations into Trump foes that have raised questions about whether the law enforcement agency has been turned into a political weapon.

The SPLC has faced intense criticism from conservatives, who have accused it of unfairly maligning right-wing organizations as extremist groups because of their viewpoints. The center regularly condemns Trump's rhetoric and policies around voting rights, immigration and other issues.

The center came under fresh scrutiny after the assassination last year of conservative activist Charlie Kirk brought renewed attention to its characterization of the group that Kirk founded and led. The center included a section on that group, Turning Point USA, in a report titled "The Year in Hate and Extremism 2024" that described the group as "A Case Study of the Hard Right in 2024."

FBI Director Kash Patel said last year that the agency was severing its relationship with the center, which had long provided law enforcement with research on hate crime and domestic extremism. Patel said the center had been turned into a "partisan smear machine," and he accused it of defaming "mainstream Americans" with its "hate map" that documents alleged anti-government and hate groups inside the United States.

House Republicans hosted a hearing centered on the SPLC in December, saying it coordinated efforts with President Joe Biden's Democratic administration "to target Christian and conservative Americans and deprive them of their constitutional rights to free speech and free association."