Former Vice President Joe Biden and the directors of the three main U.S. intelligence agencies submitted so-called “unmasking” requests for information about Michael Flynn contained in highly classified intelligence reports, according to documents released Wednesday.

The documents show that an unmasking request was made in Biden’s name on Jan. 12, 2017. Similar requests were made under the names of James Comey, John Brennan and James Clapper, the former directors of the FBI, CIA and Office of the Director of National Intelligence, respectively.

Sens. Chuck Grassley and Ron Johnson released the list on Wednesday. Richard Grenell, the acting director of national intelligence, declassified the list of names last Thursday, and provided them to the senators this week.

It is not clear whether Biden or the other intelligence chiefs saw the documents related to Flynn. The document released on Wednesday said that the unmasking requests were made under 16 different government officials’ names.

“Below is a list of recipients who may have received Lt. Gen Flynn’s identity in response to a request processed between 8 November 2016 and 31 January 2017 to unmask an identity that had been generically referred to in an NSA foreign intelligence report,” the document stated.

“While the principals are identified below, we cannot confirm they saw the unmasked information.”

Flynn spoke by phone on Dec. 29, 2016, with Kislyak.

Days after the call, FBI and Justice Department officials began discussing whether Flynn violated the Logan Act, an obscure law that prohibits American citizens from negotiating with foreign governments regarding U.S. government policy.

Unmasking describes the process where high-level U.S. government officials request to see information regarding American citizens mentioned in classified transcripts of communications involving foreigners. It is not illegal to make unmasking requests. But the Flynn case is unique because the mentions of him in the classified transcripts was leaked to the media.

David Ignatius, a Washington Post columnist, mentioned the call and the possible Logan Act violation in a Jan. 12, 2017, column.

WaPo’s source has still not been identified.

The Justice Department filed a motion to drop the case against Flynn May 7 for making false statements to the FBI regarding his conversations with Kislyak.

Flynn pleaded guilty on Dec. 1, 2017, to the false statements charge.

The Justice Department filed its motion to drop charges against Flynn citing new FBI documents discovered in the case.

Grenell, who also serves as ambassador to Germany, took the list of names to the Justice Department last week asking for the information to be released to the public. Grenell has been behind a recent push to declassify and release documents related to the FBI’s investigation of Trump associates.

He was involved in the process of declassifying footnotes from a Justice Department inspector general’s report on the investigation. Those footnotes showed that the FBI received evidence in 2017 that Russian intelligence operatives might have fed disinformation to Christopher Steele, the author of a dossier that accused the Trump campaign of conspiring with the Kremlin.

Grenell also recently pressured House Intelligence Committee Chairman Adam Schiff to release 53 transcripts of interviews that the committee conducted as part of its own Russia probe. The transcripts showed that Obama officials such as James Clapper, Susan Rice and Ben Rhodes had not seen evidence of collusion between the Trump campaign and Russia by the time they left office.