Mr Crowther was in a stable but critical condition yesterday more than 24 hours after he lost control of his Rolls-Royce and veered off the M5 in Gloucestershire on Saturday. He underwent surgery to remove a blood clot on his brain after the accident near Cheltenham. His car was the only vehicle involved.
Lyn Hill-Tout, general manager of Frenchay Hospital, Bristol, where Mr Crowther is in the intensive care unit, said: 'He has stabilised after the operation and has shown some slight signs of improvement.'
Mr Crowther, 59, of Corston, near Bath, who hosted the television shows Crackerjack and The Price is Right, was returning home from opening a shopping centre in the Midlands when he lost control of his car and it ended up on its roof on the hard shoulder.
Inspector Mervyn Watts, of Gloucestershire police, said yesterday: 'His vehicle will be examined . . . to see if there was a mechanical defect. But as it is a Rolls-Royce it does not seem all that likely that there was a defect. He could have had a blow-out or he might have swerved to avoid something.'
He said that police had asked for permission to carry out a breath test on Mr Crowther but the request was refused by doctors. This was a routine procedure and there was no suggestion that alcohol was a factor in the crash.