Congressional Democrats’ impeachment inquiry into President Donald Trump backfired again on Tuesday when one of the star witnesses, Lt. Col. Alexander Vindman, admitted Hunter Biden seemed unqualified to hold an $83,000-per-month job with Burisma Holdings.

Testifying before the House Intelligence Committee, Vindman told lawmakers he believed Hunter Biden, the youngest son of former Vice President Joe Biden, did not have the necessary qualifications to be on Burisma’s board of directors.The company, which is Ukraine’s only private oil and gas conglomerate, became central to the impeachment inquiry after Trump suggested the Ukrainian government probe the firm and its ties to the younger Biden.

Democrats argued the president’s suggestion that Ukraine probe the matter likely amounted to an impeachable offense at the launch of their inquiry. Trump and his allies, on the other hand, have claimed Hunter Biden’s appointment, coming around the same time his father was tapped to lead Obama-era policy towards Ukraine, and his relative inexperience in the energy industry, warrant investigation.

Vindman, who serves as the director of European affairs for the United States National Security Council, seemed to give credence to the president’s concerns on Tuesday when appearing before Congress.

“As far as I can tell he didn’t seem to be [qualified],” the lieutenant colonel said when asked about the younger Biden’s role.

Alexander Vindman: Hunter Biden "didn't seem to be" qualified to serve on the board of Ukrainian gas company Burisma while his father Joe Biden was Vice President. pic.twitter.com/0CClRlnoFb — Trump War Room (Text TRUMP to 88022) (@TrumpWarRoom) November 19, 2019

As Peter Schweizer, senior contributor at Breitbart News, detailed in his book, Secret Empires: How the American Political Class Hides Corruption and Enriches Family and Friends, Hunter Biden had no prior experience with either the energy industry or Ukraine before joining Burisma in April 2014. In fact, his background in investment banking, lobbying, and hedge fund management paled in comparison to that of current and past members of the company’s board of directors.

Adding to concerns is the fact that, at the time Hunter Biden joined Burisma, the company was seen as actively courting western leaders to prevent further scrutiny of its business practices. The same month Hunter Biden was tapped for the group’s board, the government of Great Britain froze accounts belonging to Zlochevsky under suspicion of money laundering.

Zlochevsky, a former Ukrainian minister of natural resources, would later be accused of corruption for using his office to approve oil and gas licenses to companies under his control. A Ukrainian official with strong ties to Zlochevsky admitted in October the only reason that Hunter Biden secured the appointment was to “protect” the company from foreign scrutiny. The claim has credence given that at the time, Joe Biden, as the sitting vice president, was tasked with leading the Obama administration’s policy towards Ukraine in response to Russia’s invasion of Crimea.

It is in the context of Burisma and Zlochevsky’s legal troubles that Joe Biden’s political influence has raised the most red flags. The former vice president has particularly drawn questions over his conduct in demanding the Ukrainian government fire its top prosecutor, Viktor Shokin, in 2016.

Joe Biden, who has publicly bragged about the firing, reportedly threatened to withhold more than one billion dollars in U.S. aid if the Ukrainian government did not remove Shokin. He has claimed the demand came from then-President Barack Obama, who had allegedly lost faith in the prosecutor’s ability to tackle corruption.

Unofficially, though, it was known that Shokin was investigating both Burisma and Zlochevsky for public corruption. It is uncertain if the probe extended to Hunter Biden, although Shokin has recently admitted that prior to his ouster he was warned to back off the matter. Regardless of what occurred, Shokin’s successor, who is now himself being investigated for public corruption, dropped the investigation into Burisma and Zlochevsky.

When asked about Biden orchestrating the pressure campaign on Ukraine to fire Shokin on Tuesday, Vindman refused to characterize the former vice president’s conduct as “wrong.” Vindman’s refusal came despite the fact that another of the inquiry’s star witnesses, former U.S. Ambassador to Ukraine Marie Yovanovitch, testified on Friday that Shokin’s probe into Burisma was still open at the time of his dismissal.

It wasn’t an active case, but it also was not fully closed,” Yovanovitc told lawmakers, before elaborating that at the time Shokin was opting to keep a “hook” into Burisma and Zlochevsky.