Alabama Attorney General Steve Marshall has launched a civil investigation into the Southern Poverty Law Center (SPLC), issuing a subpoena over its fundraising and use of donations following a related federal indictment.

Marshall said the probe will examine whether the organization violated state laws on charities or deceptive trade practices.

The U.S. Department of Justice has separately accused the SPLC of fraud related to payments to informants inside extremist groups, an allegation the group strongly denies.

The SPLC says its informant program was used to gather intelligence to prevent attacks and help law enforcement target hate groups, the AP has reported.

The organization, which frequently clashes with conservative figures and the Trump administration, says it is reviewing the subpoena while rejecting claims of wrongdoing.