The Department of Justice handed over a cache of documents to Michael Flynn’s attorneys this week, after an internal review ordered by Attorney General William Barr.

The documents “involved the analysis of reports related to the investigation along with communications and notes by Federal Bureau of Investigation (FBI) personnel associated with the investigation,” prosecutors say, according to The Hill.

Though it’s unclear what exactly is in the documents, the handover could suggest prosecutors withheld possible exculpatory evidence, or anything which might help Flynn’s defense, from his legal team before trial.

Flynn, a former National Security Advisor to President Trump, pleaded guilty in December 2017 to charges of lying to the FBI surrounding several of his dealings with Russia’s ambassador to the United States.

Since then, he has been agitating to reverse his plea, after firing his original legal team.