The daughter of a woman who died in a Belfast emergency ward believes her mother may have lived if she had not had to wait so long for treatment.
Health Minister Edwin Poots is under pressure after it emerged that long waiting times and staff shortages contributed to five deaths in one A&E unit last year.
First Minister Peter Robinson was forced to defend his under-fire DUP minister as the row over emergency care deepens.
Last night, the daughter of a patient who died said her mother had been triaged when she was brought in, but she believed it had been done incorrectly.
"Mum was left for hours in A&E," she told BBC's Nolan Show.
"She had been left for some time and we feel because she was left for so long that may have contributed to her death."
Despite growing concerns over the safety of hospital care, Mr Poots insisted yesterday that there is no healthcare crisis. Last night Mr Robinson said Mr Poots had a "very difficult task".
He added: "I make this very clear, if Edwin comes to the Executive on the basis of advice from professionals within his department and indicates that the issue is about finance, then my hand will go up to give him whatever support he requires."
Mr Poots faced intense questioning at Stormont yesterday after it emerged three families of five patients at Belfast's Royal Victoria Hospital where delayed treatment was a factor in their deaths were not informed of full details.
During an at-times heated Health Committee session, Mr Poots staunchly defended the safety standards of the current system.
When asked by the SDLP's Fearghal McKinney if he now accepted there is a crisis, the minister replied: "No, I don't accept there is a crisis.
"Five people dying in hospital of 80,000 being treated is not a crisis. And if it is a crisis, the entire UK hospital system is in crisis."
He said the deaths would be investigated, adding: "We should stop damning our emergency departments because they respond very, very well to people and they provide excellent care to people."
Flanked by Chief Medical Officer Dr Michael McBride, Department of Health Permanent Secretary Dr Andrew McCormick and Dr David Stewart from watchdog Regulation and Quality Improvement Authority, he told the committee that A&E departments in Northern Ireland had lower mortality rates than in England.
"That is a very important message that the public need to hear – hospitals in Northern Ireland are performing safely."
A statement from the Belfast Trust confirmed that not all of the families have been informed.
"Some have said that they do not wish any further information. However, for those that do, we are going back to ensure that they are fully informed," it said.
SDLP's Fearghal McKinney: "The issue here is you were clearly playing down the incident and that we only have now learned through information coming out from the professionals to the media, we've only found out about these things. How does this service learn anything about improving if these details were not going to come out?"
Chief Medical Officer Michael McBride: "I would have to take issue with this. These five incidents were reported as serious adverse incidents by the very Trust that was providing their care. Of those five cases three of them are still undergoing investigation. The degree of scrutiny is basically insured by the health and social care and our Public Health Agency."