Thousands of cases are being re-examined

Dr Bill McConnell said Altnagelvin Hospital was satisfied that the original diagnosis on 11 significant patients had been correct.

About 8,000 examinations at three NI hospitals are ongoing amid concerns about the consultant's work.

Dr McConnell said staff in Londonderry had performed an "outstanding job".

"All of the patients screened during the period that was giving some concern have been looked at," the director of public health medicine said.

The individual records of all of those 11 have now been checked and reviewed by the leading Commission for Breast Cancer services and they have all been cleared Dr Bill McConnell

"We had got to a point yesterday, coming up towards lunch-time, where we had been able to clarify things down from the initial very high number to 11 patients.

"The individual records of all of those 11 have now been checked and reviewed by the leading Commission for Breast Cancer services and they have all been cleared."

Checks are also under way at Belfast City and Antrim Hospitals where the doctor worked.

Antrim Hospital said 5,000 cases in which the consultant had had some involvement are to be reassessed.

Belfast City Hospital said 2,000 cases would be reviewed .

The health minister held a news conference on Monday

The consultant was employed at Altnagelvin until 2003. At a news conference on Monday, Health Minister Shaun Woodward and representatives of the three hospitals said they wanted to assure the public that the measures being taken were precautionary and the risk to patients of a mistake having been made was low.

The health minister has asked Dr Robin Wilson, director of Breast Screening Quality Assurance in the East Midlands, to lead an investigation into the consultant's work.

Helplines have been set up for anyone concerned about their breast screening result.