A leading hospital trust has launched an inquiry following claims that an anaesthetist fell asleep during an operation.
The medic was allegedly caught sleeping in an operating theatre during surgery at Selly Oak Hospital in Birmingham.
The University Hospital Birmingham NHS Foundation Trust refused to comment on the reports, saying only: "An investigation is under way."
The head of Birmingham City Council's health scrutiny committee, Deirdre Alden, said she was concerned about the claims if proved correct.
"Something like this could really knock patient confidence and the hospital needs to carry out a thorough investigation very quickly," the councillor said.
"The public must have 100 per cent confidence that the hospital is doing their best for them but if someone has been caught sleeping on the job it is totally appalling.
"We need reassurance that this will be dealt with properly and not pushed under the carpet."
More than 6,500 people work at the trust, which runs both Selly Oak and the nearby Queen Elizabeth Hospital.
More than 553,000 patients are treated there annually.
UHB, which also houses the Royal Centre for Defence Medicine, was last year given the go-ahead to become one of England's first NHS foundation trusts.
Work has begun on a £ 521 million hospital to replace the QE and Selly Oak in the largest scheme of its kind outside the capital.