Senate Judiciary Chairman Chuck Grassley wants to know more about the memos former FBI Director James Comey shared with his friend working as a Columbia Law School professor.

Grassley, R-Iowa, is asking Deputy Attorney General Rod Rosenstein to tell him when the seven memos were made classified and by whom. He also wants to know about the “chain of custody” of the memos, of which four have been marked classified at various levels.

Comey wrote seven memos recollecting his conversations with President Trump about the FBI’s Russia investigation, telling the Senate Intelligence Committee in July 2017 that he considered the four memos he shared with law professor Daniel Richman at Columbia University to be personal documents.

“I understood this to be my recollection recorded of my conversation with the president. As a private citizen, I thought it important to get it out,” Comey told lawmakers of the memos he shared, which included one memo that he asked Richman to leak to the news media with the hopes it would prompt a special prosecutor in the Russia investigation.

Trump fired Comey in May 2017, and Rosenstein appointed special counsel Robert Mueller to take over the investigation into Russian meddling in the 2016 election and possible collusion with the Trump campaign.

Grassley also asks Rosenstein in the Wednesday night letter to disclose whether the Justice Department has attempted to see if Richman was given classified information, and if so, if the disclosure or disclosures violated department rules or policy.

Grassley said he reviewed the memos in a secure environment on Capitol Hill, and that “only three did not contain classified information.”

“If it’s true that Professor Richman had four of the seven memos, then in light of the fact that four of the seven memos the Committee reviewed are classified, it would appear that at least one memo the former FBI director gave Professor Richman contained classified information,” Grassley wrote, noting that Richman refused to give the Senate Judiciary Committee the memos he had received from Comey and has not said whether he still has copies.

Richman has apparently turned over copies of the memos to Mueller, while continually refusing to give them to Grassley’s committee.

Richman declined to comment to the Washington Examiner, and the Justice Department did not immediately respond to a request for comment.

“Please describe what steps the FBI has taken to recover all copies of any classified memoranda that might reside on computers, servers, or at other locations,” Grassley wrote, adding he also wants to know if anyone from the FBI or Mueller’s office discussed with Richman the Senate Judiciary Committee’s request for copies of the memos.

Grassley wants answers from Rosenstein no later than Jan. 17.