Hunter Biden, the youngest son of former Vice President Joe Biden, is allegedly the subject of a criminal investigation relating to money laundering with Burisma Holdings, according to documents filed in Arkansas court.

The New York Post reported on Monday that a private investigator hired by Lunden Roberts, a woman suing Biden for child support in Arkansas circuit court, has declared he is the subject of multiple criminal investigations.

“One of those purported investigations relates to Burisma Holdings, the Ukrainian energy company with which Biden held a lucrative board post while his father, Joe, was vice president — drawing allegations of impropriety from Republicans including President Trump,” the Post noted.

The private investigator claims the younger Biden “established bank and financial accounts with Morgan Stanley” for a “money laundering scheme” involving Burisma Holdings Limited. According to documents filed in court, nearly $6.8 million was transferred from Burisma to the account between March 2014, when the younger Biden joined Burisma’s board of directors, and December 2015.

Court filings also allege that Biden and a group of business associates “utilized a counterfeiting scheme to conceal” the payments.

The revelations come as Hunter Biden’s role with Burisma continues to draw scrutiny, especially in light of the impeachment of President Donald Trump.

Congressional Democrats claim that Trump’s suggestion the government of Ukraine looking into Hunter Biden’s work with the natural gas company amounted to asking a foreign power for dirt on a political opponent. Trump and his allies, on the other hand, have countered that Hunter Biden’s appointment, coming around the same time former Vice President Joe Biden was tapped to lead Obama-era policy towards Ukraine, and his relative inexperience in the energy industry warrant investigation.

As Peter Schweizer, senior contributor at Breitbart News, detailed in Secret Empires: How the American Political Class Hides Corruption and Enriches Family and Friends, Hunter Biden’s background in investment banking, lobbying, and hedge fund management paled in comparison to that of current and past members of Burisma’s board.

The elder Biden claims he has never talked to his son about his business in Ukraine, but the former veep has yet to answer questions about a photograph showing him, Hunter, and another Burisma board member playing golf together in 2014.

Adding to concerns is the fact that, at the time Hunter Biden joined Burisma—where he was paid as much as $83,000-per-month—the company was seen as actively courting western leaders to prevent further scrutiny of its business practices. The same month Hunter Biden and Kwasniewski were tapped to join the group’s board, the government of Great Britain froze accounts belonging to Burisma’s founder, Mykola Zlochevsky, under suspicion of money laundering.

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 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.

Since the start of impeachment, the Ukrainian government has reopened its case into Zlochevsky, this time broadening the investigation to include public corruption and embezzlement.