A gastroscope was used to examine patients

The Department of Health said on Tuesday that 17 gastroscopes out of more than 1,000 used in Northern Ireland had "queries over their decontamination process".

Further investigations are being carried out to see whether any patients have been put at risk.

The equipment is used to detect problems in the throat and stomach, and has to be sterilised after each use.

A health scare earlier this month at a hospital in Lisburn, County Antrim, prompted an audit of all such equipment at the weekend.

It is unacceptable - I believe it has been mis-managed Jane Graham Eastern Health and Social Services Council

In the first incident, more than 400 patients were offered blood tests after it emerged they had been treated at Lagan Valley hospital with a gastroscope which had not been properly sterilised.

Those patients were offered a meeting to discuss if they wished to have blood tests to establish if they had a blood borne infection like HIV or hepatitis.

Jane Graham from the watchdog body, the Eastern Health and Social Services Council, said the latest revelations were very disturbing.

"It is unacceptable. I believe it has been mis-managed," she said.

"We want to know why a rigorous audit wasn't carried out until last weekend... two months on.

"We want to know who carried out that audit, how rigorous was that audit and what standards were they measuring this against?"

GASTROSCOPES Small flexible tube with a light and camera at the end Passed down patients' throats Used to check for conditions like ulcers, and to take tissue samples Must be sterilised after every use Cleaning must be done carefully with chemicals, as microscopic infections could be present

However, Chief Medical Officer Dr Etta Campbell denied Ms Graham's allegation and said the Department of Health was taking affirmative action and proceeding with urgency on the matter.

"What people need to know is that following the Lagan Valley incident - recognising that there may have been a problem with that scope - we did ask all trusts to clarify whether or not they were seeing the same problems with those scopes," she said.

"What we have done since then is to look at all scopes. We have taken the initiative to look at all scopes in use throughout Northern Ireland."

In a statement issued on Wednesday, the Department of Health said: "The department has responded promptly and urgently following the incident at Lagan Valley Hospital.

"An audit of all endoscopes has been made against the highest international standards in the interests of patient safety. This was the appropriate and proper course of action.

"Each Trust is responsible for ensuring that its practices and procedures are in order. The department has the role of ensuring that the systems operated by the HPSS are in line with proper standards and best practice."

Jane Graham said the latest revelations were very disturbing

The results of the further investigations are expected to be known in the next few days.

The Department of Health says it will only contact patients if any of the equipment under investigation is shown to have carried a risk of infection.

It says this risk is much less likely than in the earlier Lagan Valley case.

The Department says that since the outbreak of Sars and the potential threat of a flu pandemic, infection control in Northern Ireland's hospitals means they are now safer than they were six months ago.

A helpline has been set up for anyone who is concerned: 0800 9120099.