Baiden, the son of President-elect Joe Biden, was under investigation for foreign travel while he was vice president.

Hunter, the son of President-elect Joe Biden, said Wednesday that his “tax issues” are under federal investigation and has shed new light on questions about his financial dealings that led to his father’s publicity campaign.

In a statement released by the Office of the President-elect Transformation, Junior Beadon said he learned of the investigation Tuesday. He did not elaborate.

“I take this issue very seriously but I am sure that a professional and purposeful review of these issues will prove that I have managed my issues legally and appropriately with the benefit of professional advisers,” he says.

Hunter Biden has long been a target of President Donald Trump and his allies, who have accused him of profiting from his political connections. Trump and his supporters also raised irresistible allegations of corruption related to Hunter Biden’s work on Uniter when his father was vice president and led the Obama administration’s business with Eastern European nations.

The revelation of a federal investigation led by the Delaware U.S. Attorney’s Office came at a worrying moment for the incoming president, who is assembling his cabinet. His election on behalf of the attorney general could oversee the investigation into the new president’s son if Biden still continues to be sworn in on January 20.

The transformation team said in a statement: “President-elect Biden is deeply proud of his son, who has fought through tough challenges, including the horrific personal attacks of recent months, just to be strong.”

Hunter Biden’s lawyers did not immediately return a call seeking comment.