Biden's doctor, O'Connor, refused to answer questions about his legal capacity.

Kevin O'Connor, the doctor of former US President Joe Biden, refused to answer questions at a congressional hearing on July 11 about whether Biden was capable enough to serve as president.

"On the advice of my lawyer, I am forced to respectfully decline to answer, based on medical confidentiality and on my right guaranteed by the Fifth Amendment to the Constitution. I am not a lawyer and I am obliged to follow the advice of my lawyer in this matter," O'Connor said, answering a question about Biden's legal capacity, the hearings were broadcast on The New York Post's YouTube channel.

With his answer, the doctor used the right not to testify against himself.

What he was thinking: The U.S. Senate is investigating Biden's health condition

The examination will check the mental abilities of the ex-president

On June 4, US President Donald Trump ordered an investigation into Biden's health condition. It was noted that Biden had suffered from severe cognitive impairment for many years, as a result of which his assistants could take advantage of the situation and use autopilots to sign important documents for selfish purposes.