US President-elect Joe Biden’s son Hunter has said his tax affairs are under investigation.

The investigation is being conducted by federal prosecutors in Delaware.

Hunter Biden said he took the case “very seriously” but was confident an “objective review” would show he had handled his affairs “legally and appropriately”.

The Biden-Harris transition team said the president-elect was “deeply proud of his son”.

A statement from the team said Hunter had “fought through difficult challenges, including the vicious personal attacks of recent months, only to emerge stronger”.

Hunter Biden said he learned of the investigation on Tuesday. He did not disclose any further details, BBC reported.

The 50-year-old was a frequent target of Republican criticism during the 2020 election campaign, focusing on his business dealings in Ukraine and China when Joe Biden was vice-president in the Barack Obama administration.