Peter Curran went on holiday and is not due back for a week, St Mary's Hospital, Sidcup, Kent, said last night.
The allegations were made in the News of the World yesterday. The hospital was swamped with anxious callers and had to set up seven telephone lines to provide counselling and advice.
Stephen Collinson, the hospital's chief executive, said that until the surgeon contacted officials, he could respond only to the allegations in the newspaper. 'We still have been unable to contact him and therefore we cannot confirm or deny the allegations. He has contacted one of his colleagues, but only to say he would not confirm or deny the story.'
He said Mr Curran had worked at St Mary's for 10 years, carrying out 140 operations a year, mainly on elderly people.
Officials emphasised there was little risk to patients, with no incident in Britain or elsewhere in which surgeons had transferred the virus to patients during operations. 'My concern is that the patients would be alarmed by the article,' Mr Collinson said.
Dr Elizabeth Dean, director of public health for Bexley Health Authority, said: 'We are reassuring people that so far as we can tell from the expert advice that we have received, there is no risk at all that they could have got HIV.'
Later, Mr Collinson said the helpline closed down at 8pm after receiving 310 calls. 'It would be fair to say that one-third of those who telephoned had been operated on in the last seven years by the surgeon named in the article.'
Twenty-five people requested Aids tests after speaking to the counsellors. The helpline will operate today 'and will be open for as long as it is needed'. Local GPs have been given information to help any worried patients.