April 21 (UPI) -- The Southern Poverty Law Center announced via YouTube Tuesday that it is now the target of an investigation by the Department of Justice.

"Although we don't know all the details, the focus appears to be on the SPLC's prior use of paid confidential informants to gather credible intelligence on extremely violent groups," said CEO Bryan Fair in the video. "This use of informants was necessary because we are no stranger to threats of violence. In 1983, our offices were firebombed, and in the years since, there have been countless credible threats against our staff."

The Southern Poverty Law Center is a nonprofit advocacy and litigation organization that tracks White supremacist and other hate groups in the United States. Republicans have criticized the nonprofit for acting as a far-left entity that they say targets conservative organizations and people. It was founded in 1971 by Morris Dees, Joseph Levin Jr. and Julian Bond as a civil rights law firm in Montgomery, Ala.

The case is being led by the U.S. Attorney's Office for the Middle District of Alabama, CBS News reported.

Fair said the probe is targeting the organization and its employees.