Veteran rock climbers have cast doubt over a dad's claims his eight-year-old son became the youngest person ever to climb one of the US' most fearsome cliff faces.
Critics have accused the Bakers of using previously rigged ropes and a scaling device called an ascender.
Tommy Caldwell, a well-known scaler of El Capitan, said: "Theoretically I could have put (my son) in a haul bag when he was 1 year old and gotten him up there" to claim the record.
