A lawyer who played a crucial role in the White House’s handling of President Trump’s Ukraine call told the National Security Council’s Ukraine expert not to discuss the call with others, according to a Politico report on the expert’s congressional testimony.

The claim is likely to raise more questions about whether the lawyer, deputy White House counsel John Eisenberg, sought to stifle concerns being raised about the call, in which Trump asked President Volodymyr Zelensky to launch investigations into his political rivals.

The House has requested to depose Eisenberg later this month. It is unclear whether Eisenberg will participate in the House’s impeachment probe, or whether, if subpoenaed, he’d comply with it.

The claim about his directive was made by Army Lt. Col. Alexander Vindman in his closed door deposition earlier this week, Politico reported. Vindman found Eisenberg’s directive disturbing, Politico reported, in part because his job on the NSC includes coordinating the administration’s Ukraine policy across various agencies.

Vindman listened in on the July 25 Trump call, and, in his prepared testimony that was made public, said he was “concerned” by it. He reported his concerns to Eisenberg, having already flagged to Eisenberg earlier his concerns about a discussion a U.S. ambassador had with Ukraine officials about opening the probes.

Eisenberg told Vindman not to talk about the call with others a few days after Vindman had reported the call to him, according to Politico’s report of his testimony.

Eisenberg, who serves as the chief lawyer for the NSC, pops up in several key moments during the fallout in the White House from the Ukraine pressure campaign.

He twice fielded concerns from Fiona Hill, another NSC aide at the time, and other officials raised the alarm to him, according to a Washington Post report.

He was behind the decision to put the White House’s transcript of the call into a hyper-secure system usually reserved the most sensitive of operations, CNN reported.

He was also told by the CIA’s top lawyer that a whistleblower, through a colleague, had alerted her to the call. He and the CIA lawyer told the Justice Department about the call on Aug. 14, NBC News reported. That prompted a DOJ review of the call record well before it was referred to in the complaint the whistleblower later filed with the inspector general of the intelligence community.

The NSC press office did not respond to a TPM email seeking comment on the report of Vindman’s testimony.