Edinburgh City Council has confirmed that it is unable to find places for hundreds of elderly residents who need residential care as 15% of the city's care home capacity is regarded as unsuitable.
Basing its decisions on verdicts from care inspectors, the council is not willing to use beds in homes not deemed to meet adequate standards. Several city homes, including three run by Bupa, are currently not allowed to take new referrals.
The Care Inspectorate recently said Pentland Hill nursing home in Corstorphine, where police are investigating four deaths, had improved, but that admissions should remain suspended.
Inspectors said the home, which houses more than 80 people, was not providing all residents with food they could eat or enough fluids, and warned of understaffing and a high rate of agency staff use.
The council is also not placing any admissions at Bupa's Braid Hills or Victoria Manor homes due to concerns about standards raised by inspectors, while other smaller homes run by other companies are also currently off limits.
An Edinburgh City Council spokeswoman said: "Approximately 15% of care home capacity in Edinburgh is currently unavailable due to concerns about the standards of care reported by the Care Inspectorate.
"This is an unusually high figure and is creating a care home capacity problem which has been reported to NHS Lothian. It is putting significant pressure on us to meet delayed discharge performance targets.
"We are working closely with all care home providers and the Care Inspectorate to improve standards of care across the city and address any concerns raised."
Scottish Labour's Health spokesman Neil Findlay said: "This is worrying and begs the question of whether this situation is reflective of health boards across the country.
"We know many of our elderly citizens are stranded in hospital beds because they can't get into care homes and it seems this is because they are just not fit for purpose. This bed blocking clogs up the system and has a knock on effect across hospitals."
"City of Edinburgh Council is right not to use private care homes that the care inspectorate say are not fit for purpose."
He said health minister Alex Neil should tackle the problem.
He said: "We need a more integrated inspectorate for health and social care across Scotland, one that has teeth and the power to hold regular unannounced inspections, send in change teams to take over failing public health services and refer criminal failures to the Crown Office. It would provide the public and patients with a single point of focus for complaints and for improvement.
"This crisis is another example which illustrates the need to hold a full scale inquiry into our health service. I have been calling for this since I came into post but Alex Neil refuses to even acknowledge there is a problem.
"If elderly patients being denied beds because they aren't up to standard doesn't encourage him to act then I don't know what will."
A Scottish Government spokeswoman said: "We have made great progress over the last seven years in tackling delayed discharges. In 2006, there were 617 patients delayed for more than four weeks. At the October census there were 156, the lowest level ever recorded at an October census.
"We have set challenging targets and it should be recognised that 14 out of 32 local authority areas recorded no delays over four weeks.
"We are taking this even further by asking local partnerships to ensure no-one is delayed for more than two weeks by April 2015."