President-elect Joe Biden told Stephen Colbert on The Late Show with Stephen Colbert he is “not concerned” about accusations against his son Hunter Biden amid the investigation by federal prosecutors into his son’s tax affairs.

Biden sat alongside his wife, Dr. Jill Biden, and expressed that they had ” great confidence in our son.”

“I am not concerned about any accusations made against him,” President-elect Biden continued. “It’s used to get to me. I think it’s kind of foul play.”

The Biden transition team clarified that Biden was not referring to the investigation as “foul play,” but to Republicans who used Hunter Biden’s business dealings to go after him personally for months, Fox News reported.

The Delaware U.S. Attorney is currently working with the IRS Criminal Investigation agency and the FBI to investigate Hunter Biden’s taxes. The investigation has been ongoing since 2018 but was only recently publicly disclosed.

Investigators have been examining multiple financial issues, including whether Hunter Biden and his associates violated tax and money laundering laws in business dealings in foreign countries, specifically China.

Hunter Biden’s involvement with Ukranian energy company Burisma in 2014 has also been under intense scrutiny. NBC News published emails this week which show Hunter Biden had $400,000 in unreported income from his time at Burisma Holdings.

“Look, it is what it is,” Joe Biden said. “He’s a grown man. He’s the smartest man I know. I mean, in a pure intellectual capacity. As long as he’s good, we’re good.”