The House Intelligence Committee has asked the former CEO of President Donald Trump’s 2016 presidential campaign, Stephen K. Bannon, to appear before them for an interview as part of their ongoing investigation into Russian meddling in the 2016 election.

Bannon received a letter this week from the committee. In the letter, the committee requests that he appear in early January, according to Bloomberg:

“The invitation, which didn’t come in the form of a subpoena compelling them to testify, was for a “voluntary interview” in the committee’s offices, which means it would be held behind closed doors, the official said.”

Former Trump presidential campaign manager Corey Lewandowski also received a letter requesting he speak with the committee in January.

The report further reveals that the letters to Bannon and Lewandowski don’t specify reasons for the interview beyond relation to the committee’s ongoing investigation into any Russian meddling in the 2016 election. At the time of the report, the committee had not received responses from either Bannon or Lewandowski.

After the Trump campaign win in November 2016, Bannon came on board with the Trump administration as the President’s chief strategist.

The committee is also slated to conduct interviews with longtime Trump associate Rhona Graff and Trump associate Felix Sater, according to the Independent.

The committee also interviewed Erik Prince in late November.

Chairman Devin Nunes heads the House Intelligence Committee and Rep. Adam Shiff is the ranking Democrat. Reports have indicated the committee’s investigation may finally be coming to a close. NBC reported earlier this week that senior Republicans on the committee expect to wrap up the probe within weeks. Rep. Tom Rooney told the outlet that they’re “getting into the fifth and sixth level of people coming in here, then you’re spinning your wheels.”

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