The criminal case involving the owner of the natural gas company where Hunter Biden once served on the board is now under review.

The case of Burisma Holdings is one of 15 high-profile investigations that is planned to be re-examined by the prosecutor general, Ruslan Ryaboshapka, who took office in August.

It dates back to 2014 when the owner of Burisma Holdings, Mykola Zlochevsky was reportedly under investigation for money laundering and fraud and Hunter Biden got on its board.

The prosecutor general in charge of Mykola Zlochevsky’s case was removed from office in 2016 at the request of the then-Vice President Joe Biden, reported The Hill. 

President Trump asked the Ukraine president to “investigate the case” in a phone call, which triggered a whistleblower ‘s complaint. The White House then released a transcript of the call, which did not show the president abusing power or seeking help from a foreign government to undermine his political opponent, as the Democrats had claimed.

President called his move merely part of “drain the swamp'” at his interview with reporters on Monday, Sept. 30.

He asserted in his recent tweet:

From Ukraine’s end, former prime minister of Ukraine Mykola Azarov also called on the Ukrainian government to probe the activities of U.S. presidential candidate Joe Biden’s son to determine whether he broke Ukrainian law.

At the news briefing, Mr. Ryaboshapka said he had not received any phone calls about the cases or come under undue pressure on other matters. “No foreign or domestic politicians, officials, or people who are not officials called me and tried to influence my decisions on specific criminal proceedings,” he said.

He also claimed that the investigation is beyond politics and he will react accordingly if a sign of violations emerges.

The length of his audit has not been announced.