Mark Sandy, a career staffer in the White House Office of Management and Budget, told impeachment investigators that two budget staffers left the agency after expressing frustrations about the unexplained hold on Ukrainian aid, according to new closed-door transcripts released Tuesday.

Sandy said that one staffer, who worked in OMB’s legal office and whose name was undisclosed, told him they were leaving the agency, at least in part, because of their concerns regarding the hold on Ukraine security assistance.

Sandy, who is the deputy associate director for national security Programs at OMB, testified behind closed doors before the House Intelligence Committee, one of the committees leading the impeachment inquiry, on Nov. 16. He is the first OMB staffer to testify in the inquiry.

Sandy was asked specifically whether he knew this was a reason the legal office OMB staffer left.

"I never want to attribute that as the, you know, sole purpose for an individual's actions, but I am aware of their frustrations in that area, yes," Sandy said.

Sandy said that the "best way to characterize" the legal office staffer’s concern "would be a dissenting opinion vis-a-vis the Impoundment Control Act," which is a law passed under President Richard Nixon to set restrictions on a president deferring Congressionally-allocated spending funds.

Several witnesses have testified in the impeachment inquiry launched by House Democrats that there were concerns within the administration whether Trump’s hold on the Ukraine aid might violate this law. Democrats have seized on the aid in their inquiry into President Donald Trump's efforts to pressure Ukraine to investigate his political rival.

Trump and his Republican allies in Congress have defended the president by arguing that he acted within his power to withhold military aid to Ukraine because he was concerned about the corruption in the country. This is the first instance a witness has testified that someone within the budget office resigned over frustrations regarding the release of the aid.

Sandy also testified that another staffer, whose name was also undisclosed but did not work OMB’s legal division, also left the agency after expressing concerns about the hold up with the aid.

“Yes, this individual did express frustrations,” Sandy testified, later adding, “He expressed some frustrations about not understanding the reason for the hold.”

The Pentagon was concerned about the hold as well, Sandy said. While early internal paperwork on the freeze included a footnote that “OMB understands from the Department (of Defense) that this brief pause in obligations will not preclude DOD’s timely execution of the final policy direction,” that footnote was removed in late August, he testified.

"DOD stated it could no longer support that sentence," Sandy said. "They were concerned about execution risk associated with an ongoing hold," worried it could lead to a violation of the Impoundment Control Act, Sandy said.

Sandy said he was not given any reason for the freeze until September after news of the hold had become public and there was bipartisan pushback from Congress. House Democrats also announced on Sept. 9 they were investigating Trump and his personal lawyer Rudy Giuliani's efforts to pressure Ukraine into helping his re-election. At the same time, Democrats were also demanding the Director of National Intelligence turnover a whistleblower complaint that had been filed in late August.

Trump ordered the money to be released on Sept. 11.

Sandy testified it was around that time his boss gave him a reason for the hold — "that the president’s direction reflected his concerns about the contributions from other countries for Ukraine."