US officials have announced fraud charges against the Southern Poverty Law Center (SPLC), a civil rights group that tracks extremist organisations and played a prominent role in confronting the Ku Klux Klan (KKK).

In a news conference on Tuesday, Acting Attorney General Todd Blanche accused the non-profit of secretly funding the very groups that it says it opposes, through paying informants who infiltrated them - including within the KKK.

An indictment charges the SPLC with six counts of wire fraud, four counts of bank fraud and one count of conspiracy to commit money laundering.

The organisation's president has said they would vigorously defend ourselves, our staff, and our work. The SPLC has long had a sour relationship with the Trump administration and has been accused by some Republicans of unfairly targeting conservative groups.

Bryan Fair, the SPLC's interim leader, stated that their use of informants was essential due to threats of violence against them, recalling a firebomb attack in 1983.

The DOJ's indictment alleges that the SPLC paid over $3 million to individuals linked with various extremist groups, including a significant sum to individuals associated with the white nationalist Unite the Right event in Charlottesville.

Blanche emphasized that instead of dismantling these groups, the SPLC was fostering extremism by financially supporting sources that promote racial hatred. Fair accused prosecutors of weaponizing the justice system against organizations like the SPLC that protect vulnerable communities.