WASHINGTON, Dec. 9 (Xinhua) -- Hunter Biden, son of U.S. President-elect Joe Biden, said on Wednesday that his tax affairs are under investigation.

In a statement, Hunter Biden said he learned on Tuesday "for the first time" that the U.S. Attorney's Office in Delaware advised his legal counsel that they are investigating his tax affairs.

"I take this matter very seriously," he continued. "I am confident that a professional and objective review of these matters will demonstrate that I handled my affairs legally and appropriately, including with the benefit of professional tax advisors."

Joe Biden responded in a statement that he is deeply proud of his son, who has "fought through difficult challenges, including the vicious personal attacks of recent months, only to emerge stronger."

Hunter Biden, 50, is Joe Biden's second son.