Republican Rep. Buddy Carter of Georgia has called on the Department of Justice to launch an investigation into organizations funded by billionaire donor George Soros, citing concerns over possible involvement in politically motivated violence, a report said on Thursday.

In a letter sent Thursday to Attorney General Pam Bondi, Carter called for a “comprehensive and immediate” investigation into the Open Society Foundations and other groups backed by billionaire megadonor George Soros to “determine whether they are in violation of any federal laws related to domestic terrorism, material support for violence, or other illegal activities targeting Americans based on political beliefs.”

“There is growing concern, based on credible reporting, that George Soros’ Open Society Foundations have played a significant role in funding organizations associated with promoting political extremism and engage in or endorse actions that meet the Federal Bureau of Investigation’s definition of domestic terrorism,” Carter wrote.

“The funding of organizations that engage in, support, or incite political violence must not be tolerated,” Carter, who is running to unseat Democratic Sen. Jon Ossoff next year, added.