Senate Homeland Security Committee Chairman Ron Johnson (R-WI) signaled Wednesday that he will request Obama administration officials, including former Vice President Joe Biden, to testify in the wake of revelations that they may have sought to “unmask” communications by retired Army Lieutenant General Michael Flynn.

“Right now we’re in the information-gathering phase of this and this obviously, from my standpoint, raises a lot more questions than it actually answers,” Johnson told reporters, according to The Hill. “We will start requesting interviews with those individuals.”

“I want to find out what you were looking at, why you unmasked an American’s identity and how you used that,” the Wisconsin Republican added, before noting that he will seek interviews with former Director of National Intelligence Clapper, former CIA Director Brennan, Obama Chief of Staff Denis McDonough, and “possibly the vice president.”

Johnson’s remarks come after acting Director of National Intelligence Richard Grenell submitted a declassified list to the Wisconsin Republican and Sen. Chuck Grassley (R-IA) of Obama administration officials who had requested names to be “unmasked” between November 8, 2016, and Jan. 31, 2017.

The list of Obama administration officials who made unmasking requests are in chronological order:

Breitbart News reported:

Those who requested “unmasking” on or after Dec. 29, 2016 include: Power, Clapper, Lew, McDonough, Dempsey, O’Sullivan, Biden, and an unnamed person. McDonough is the only person who made an unmasking request between Dec. 29, 2017 and Jan. 5, 2017.

That was the date of a key Oval Office meeting at which President Barack Obama met with several senior officials and informed Deputy Attorney General Sally Yates of the Flynn-Kislyak conversations. At that meeting, the president also discussed Comey’s plan to approach President-elect Donald Trump to inform him about salacious (and unverified) information from the “Steele dossier” at Trump Tower the next day, Jan. 6.

On Tuesday, in an appearance on ABC’s Good Morning America, Biden, who had been at the Jan. 5 meeting, initially denied knowing about the plan to investigate Flynn, then admitted that he had known that “they had asked for an investigation.”

This development comes after the Department of Justice dropped its criminal case against Flynn, who pleaded guilty to making false statements to the FBI regarding his contacts with Russian Ambassador to the U.S. Sergey Kislyak during President Trump’s transition period. The move came after revelations showing that handwritten notes compiled by FBI officials questioned whether the “goal” was “to get [Flynn] to lie, so we can prosecute him or get him fired.”

In a Wednesday press conference, Sen. Rand Paul said the published list shows Biden was “caught red-handed” using U.S. spy powers to “go after a political opponent.”

“I think it is a very serious offense and should be investigated — and the fact that Vice President Biden is directly involved with unmasking a political opponent. Think about it. Remember we went through this thing called impeachment? They said President Trump was using the government to go after a political opponent?” the senator said. “This is Vice President Biden using the spying powers of the United States to go after a political opponent. He’s caught red-handed here.”