The integrity of House Democrats was questioned after two witnesses with exculpatory evidence were not called to testify at the impeachment inquiry on the week ending Nov. 22.

Former National Security Council Special Adviser for Ukraine negotiations Christopher Anderson and his replacement, Catherine Croft, did not appear on the House Intelligence Committee’s witness list even though both of them testified at closed-door sessions at the request of Democrats back in October.

Breitbart speculated the pair could have been excluded because they previously produced evidence that could acquit Donald Trump of any wrongdoing during U.S. diplomatic relations with Ukraine.

Croft reportedly offered at least two forms of evidence that could support the president’s claim there was nothing wrong with asking Ukrainian President Volodymyr Zelenskiy to help investigate possible interference in the 2016 U.S. general election and the son of presidential candidate Joe Biden (D), Hunter, who sat on the board of Ukraine energy company Burisma.

The incumbent special adviser revealed the White House had previously withheld military aid to Ukraine back in 2017 due to concerns of corruption and doing otherwise could antagonize Russia. The previous Barack Obama administration refused to provide military aid, according to Breitbart.

“The president was skeptical of providing weapons to Ukraine,” Croft told the House Permanent Select Committee on Intelligence on Oct. 30. “When this was discussed, including in front of the Ukrainian delegation, in front of President Poroshenko, he [Trump] described his concerns being that Ukraine was corrupt that it was capable of being a very rich country, and that the United States should not pay for it but, instead, we should be providing aid through loans.”

Croft, who served on the Ukraine desk between 2015 and 2017, backed former U.S. Ambassador to Ukraine Marie Yovanovitch’s admission the previous Obama administration was concerned about a potential conflict of interest from Hunter Biden’s board role at Burisma.

“I had heard that Hunter Biden was on the board of an energy company [that was Burisma,]” she said. “It just came up, yeah, in conversation somebody was sort of annoyed that that was the case … I think just sort of a general concern about the appearance of the [then] vice president’s son doing business in Ukraine.”

She also said Vice President Biden had a “policy” interest in Ukraine.

“At the time, the vice president was very engaged on Ukraine policy,” Croft said. “He spoke several times with President Ponoshenko, and spoke to–if I recall correctly, spoke to other world leaders in support of Ukraine as well.”

Anderson backed Croft’s account that the Obama administration was concerned about Hunter Biden’s involvement with Burisma, according to Breitbart.