It’s unclear what criminality Smith contends Corcoran’s testimony could expose, but previously unsealed court records show that prosecutors convinced a magistrate who issued a search warrant in August for Trump’s Mar-a-Lago estate that there was evidence of obstruction of justice as well as potential offenses related to classified information.

The search found about 100 documents with classification markings that prosecutors contend should have been returned to the National Archives.

Corcoran did not immediately respond to a request for comment on Tuesday. A spokesperson for Smith declined to comment.

A Trump spokesperson referred to the special counsel’s investigation as a “targeted, politically motivated witch hunt,” adding: “The weaponized Department of Injustice has shown no regard for common decency and key rules that govern the legal system.”

Under court rules, Smith’s motion to compel Corcoran’s testimony would be heard by the chief judge of the U.S. District Court in Washington, Beryl Howell, an appointee of former President Barack Obama. Such proceedings are typically held in secret, although rulings sometimes become public.

Howell is set to turn over the chief judge’s post next month to a colleague, James Boasberg, also an Obama appointee.

Attorney General Merrick Garland named Smith as a special counsel in November, assigning him to take over the ongoing investigation into the sensitive documents at Trump’s home, as well as separate probes into efforts to overturn the 2020 presidential election and issues related to fundraising associated with the election and its aftermath.