President Joe Biden’s White House physician is refusing to answer questions as part of the House Republican investigation into Biden’s health in office.

Joe Biden’s White House physician on Wednesday declined to answer questions during a closed-door deposition with the House Oversight Committee, invoking his Fifth Amendment right as the Republican-led panel pushes forward in its probe of the former president’s mental fitness and decline.

Republican members of the House Oversight and Government Reform Committee balk at the refusal. Democrats say Congress should focus on the health of the people.