A U.S. State Department official told impeachment investigators on Tuesday that he raised concerns about Hunter Biden’s involvement in a Ukrainian natural gas company in 2015, telling one of then vice president Joe Biden’s staffers that the arrangement may constitute a conflict of interest, the Washington Post reported Friday.Deputy Assistant Secretary of State George Kent testified that he worried Ukrainian officials would use Hunter Biden’s position at the company, Burisma Holdings, as an opportunity to influence his father. Kent said he tried to convey his opinion to Joe Biden’s office, but that a staffer told him the vice president didn’t have the “bandwidth” to address the issue because his other son, Beau, was battling cancer.This is the first known instance in which a career diplomat tried to raise concerns regarding Hunter Biden’s business holdings in Ukraine. Several of Joe Biden’s former advisers also reportedly had discussions about whether his son’s business dealings could be seen as a conflict of interest.A former senior Biden national-security aide dismissed the issue in comments to the Post.”Did it have any effect on US policies, either on what we were doing or what the Ukrainians were doing? It didn’t,” the former aide said. “In the aggregate it didn’t have any discernible effect.”President Trump and his personal lawyer, Rudy Giuliani, have repeatedly urged Ukrainian officials to investigate the Bidens.However, Trump is currently the subject of an impeachment inquiry by House Democrats into whether Trump withheld military aid from Ukraine to pressure the country to conduct the investigations.On Thursday, White House chief of staff Mick Mulvaney appeared to confirm that the administration withheld aid to pressure Ukraine to look into interference in the 2016 presidential elections. Mulvaney quickly walked back his comments, denying there was a quid pro quo involved.