The State Department’s Inspector General has opened an internal investigation into the steps leading up to and after the suspension of the Biden administration’s special envoy to Iran, Robert Malley.

On January 23, the Inspector General’s office informed members of Congress about the probe in response to growing questions from U.S. lawmakers about Malley’s status and the reasons behind the Diplomatic Security Service’s decision to revoke his security clearance last April, according to correspondence seen by Semafor. Malley continued to perform some of the duties of the special envoy for nearly three months before the State Department officially placed him on unpaid leave in late June.

“The scope of the special review of the suspension of Robert Malley’s clearance will include the procedures the Department used in suspending the clearance as well as actions taken by the Department following the suspension,” Ryan Holden, the Inspector General’s director of congressional and public affairs, wrote in the letter. “This will include whether the Department followed proper procedures in suspending his clearance, determining what access to information he could maintain, and deciding the status of his employment.”

Holden added in his letter: “The special review will also examine which officials were involved in these decisions and how the process compares to that used for other types of employees.”