Hunter Biden, son of Joe Biden, was under federal investigation for taxes, just days before the electoral college confirmed his father's victory.

"Yesterday, I learned that the US Prosecutor's Office in Delaware had informed my legal team that they were investigating my tax matters," Hunter Biden said in a statement on Dec. 9.

"I take this very seriously but I believe that an objective and professional review will prove I have handled my work lawfully and properly, including the benefits of professional tax advisors.

The transfer team did not provide further information on the investigation, only emphasizing "President-elect Biden is extremely proud of his son, who has fought through tough challenges, including raids.

According to CNN, officials are investigating Hunter Biden's business transactions with foreign countries such as China, including potential tax and money laundering violations.

The US prosecutor's office in Delaware is headed by David Weiss, who was appointed by Trump in 2018.

Biden, 50, was born in the city of Wilmington, Delaware, where his father lives and is also the headquarters of presidential transfer operations.

The investigation was announced just five days before the Electoral College was scheduled to officially select Joe Biden as the next president.

Since 2019, Trump and his Republican allies have been attacking Hunter for deals with Ukraine and China, and there are unconfirmed reports that a Hunter Biden laptop has been neglected at

The New York Post reported in October that the Federal Bureau of Investigation (FBI) seized the computer in December 2019.

Several Republicans this week urged Attorney General William Barr to launch an independent investigation into Hunter Biden, who admits to having struggled with drug addiction and alcoholism, before Biden took office on Wednesday.

"This is why Attorney General Barr needs to appoint a special adviser to investigate Hunter Biden," Senator Ken Buck posted on Twitter following information about the tax investigation.

Hunter Biden is the only son of the President elected after his eldest son Beau Biden died in 2015 of brain cancer.