It has emerged dead bodies have been left lying on trolleys at University Hospital Waterford.
A letter by four consultant pathologists has described bodily fluids leaking on to the floor and bodies decomposing in corridors.
It has caused "unspeakable trauma" to the families of those who have died, according to the letter.
The letter, first reported in the Waterford News and Star, raises concerns over the lack of sufficient refrigeration at UHW were raised with the head of the South-South-West Hospital Group in October.
But the four doctors say no major changes have been made since.
In a statement, the HSE said that University Hospital Waterford had recently received approval for a new replacement mortuary building.
It said it expected that the request for tender will be issued shortly, with the expectation that construction will begin before the end of this year.
The HSE said that the hospital is currently examining interim arrangements to address the issues raised.
South-South-West Hospital Group has been contacted for comment, but they have not yet responded.
Labour's health spokesperson, Alan Kelly TD, has said the HSE and Government officials must react swiftly to remedy the appalling conditions.
He said that the conditions described by the consultant pathologists made for "grim, stomach-churning reading".
He said: “The Minister and the HSE need to show compassion and respect to the families who have been affected by these awful circumstances and assure them that conditions will improve at the UHW mortuary.
“The scale of the trolley crisis is already demoralising enough for the living, this type of practice must not be the norm for the dead too.“