The Justice Department has opened an inquiry into former National Security Adviser Michael Flynn‘s interview with the FBI that led to him pleading guilty of lying to investigators in 2017. He is now seeking to withdraw his guilty plea.

Attorney General William Barr reportedly asked Jeffrey Jensen, the U.S. attorney for the Eastern District of Missouri, to investigate Flynn’s interview with the FBI. They said they do not know the timeline for the inquiry, but that Jensen is looking into how the FBI’s interview of Flynn occurred.

Barr has been recently criticized for giving Trump’s allies a leg up in the justice system. On Tuesday, he lessened the sentencing recommendation for Roger Stone, a Trump associate convicted on seven charges, prompting some to accuse the DOJ of becoming partisan.

Last month, Flynn claimed the FBI interview was an ambush attack aimed at making him give false statements. Jensen’s inquiry began at approximately the same time.

The presiding judge, Emmet Sullivan said, “the Court summarily disposes of Mr. Flynn’s arguments that the FBI conducted an ambush interview for the purpose of trapping him into making false statements and that the government pressured him to enter a guilty plea.”

Flynn additionally claims his first lawyers did not provide him proper legal assistance. Prosecutors wrote in a court filing on Sunday that they will need more information from Flynn’s former lawyers to corroborate his claim.

His sentencing has been postponed to give both the prosecutors and defense lawyers adequate time to go over the new motions.