The president's son made a surprise appearance at one hearing.
The House Oversight Committee will vote on whether to hold Hunter Biden in contempt over his refusal to sit for a closed-door deposition with lawmakers.
Hunter Biden business associate tells Oversight Committee
Two House committees vote to advance Hunter Biden contempt
Hunter Biden News & Videos - ABC News
House GOP advances Hunter Biden contempt resolution after fiery
Democratic lawmaker quotes 'RHOSLC' while criticizing Donald Trump
GOP sets date for Hunter Biden deposition: reports
Hunter Biden business associate tells Oversight Committee
House GOP votes to cite Hunter Biden for contempt for defying subpoena
Hunter Biden says he would sit for deposition with new subpoena