Liver transplant operations have been cancelled by health bosses in Leeds due to a shortage of critical care nurses.
Leeds Teaching Hospitals NHS Trust has confirmed it cancelled operations and refused organs owing to a shortage of staff for high dependency and intensive care beds.
It also said the Government-imposed cap on how much NHS trusts can spend on agency staff was having an impact, and said it continued to breach the cap in order to keep safe staffing levels.
The news came to light after the Health Service Journal (HSJ) was given access to leaked documents and emails.
The NHS trust declined the offer of six livers for patients due to a lack of capacity. In a further two cases, the trust accepted the organs for patients but then had to decline them once it became clear there were "other demands" on the beds.
Suzanne Hinchliffe, deputy chief executive and chief nurse at Leeds Teaching Hospitals, said: "In two instances we have had to tell patients brought into the hospital expecting a liver transplant that their procedure could not take place because of a lack of an intensive care bed. We sincerely regret this was necessary but it was the right thing to do in the interests of patient safety.
"Our priority in these cases is to ensure the organ can be used in another hospital, and organs have not been lost because of our capacity issues.
"We acknowledge that it is extremely frustrating for patients and for the wider transplant team when capacity is not available to allow an operation to go ahead, but it would have been wrong of us to commit to these without being sure a critical care bed would be available after the procedure."
The wards affected by bed closures are at Leeds General Infirmary and St James's University Hospital.
The trust closed ward L2 at Leeds General Infirmary, and J53 at St James's.
Ward L2 is normally a four-bedded high dependency unit which has been closed since Christmas.
Two of the beds have been provided on a neighbouring ward and two beds temporarily closed, it said.
Ward J53, which is normally a six-bedded ward with a mixture of intensive care and high dependency beds, was temporarily closed on March 10.
Ms Hinchliffe said: "We have recently consolidated our critical care beds across both Leeds General Infirmary and St James's University Hospital in response to ongoing difficulties in recruiting sufficient intensive care nurses.
"As a temporary measure, beds are now concentrated in five critical care areas to ensure that we are able to maintain the highest possible standards of care.
"These changes were a formal response to existing staffing shortages that were already present prior to this time and had been leading to ad hoc bed closures across all units."
She added that very high A&E attendances had had a "knock-on effect" on demand for critical care beds.
"The picture has been similar across the region and at times this has resulted in limited availability of critical care beds across West Yorkshire.
"Hospitals across the country have been struggling to recruit sufficient qualified nurses in critical care. We did manage to attract new nurses into the unit last year and recruitment has been stepped up this year so we are expecting 44 new nursing staff to start in post in the coming months.
"This is a considerable achievement and should considerably alleviate our current staffing difficulties."
She said the trust was breaching the agency cap to provide enough staff.
"We can confirm that we have, and will continue to, breach the agency cap to address patient safety issues and in critical care the team are also looking at other incentives to improve both substantive and temporary staff recruitment."
The HSJ said the trust's online bed status system showed there was only one intensive care bed for a ventilated patient for the whole of West Yorkshire on March 17, and only one high dependency bed.
A source told the HSJ: "That's including the major trauma centre at Leeds General. Crash a car with two people in it and one of you will have to sit in A&E on a ventilator until someone else dies or gets better."
A senior clinician in the region added: "The agency cap means we're losing essential service provision and people are being harmed."
Shadow health secretary Heidi Alexander said: "This is an alarming reminder of the damage the Tories' NHS policies are doing to patient care.
"For patients in need of a liver transplant, every moment can make the difference. The fact that Leeds hospitals is having to close its doors to these patients shows how serious the staffing crisis in the NHS now is."
A Department of Health spokesman said: "We expect hospitals to have adequate staffing at all times and we are absolutely clear hospitals can override the agency cap to ensure patient safety.
"We are recruiting more nurses - there are 10,600 more nurses on our wards since 2010, with a further 50,000 in training and our changes to student funding will create up to 10,000 more training places by 2020."