A Cardiff neonatal unit has closed its doors due to concerns over "poor infection control measures", a health council has said.
The Cardiff and Vale of Glamorgan Community Health Council (CHC) said it was aware of staff having to change in toilets and equipment stored in an isolation room.
Admissions to the unit at the University Hospital of Wales stopped on Thursday because of an "infection outbreak".
Around 18 babies are currently being looked after in the unit. It is unclear what the infection is.
The CHC said that while the health board in charge of the hospital had taken urgent action to deal with the outbreak, "we believe this issue is very serious".
It added: "The CHC has continually expressed its concerns in relation to suitability of the location of the current neonatology unit due to the physical space available."
Chief officer Stephen Allen said the CHC had raised concerns during several monitoring visits.
"Following our recent visit in February of this year, our main areas of concern remained unchanged.
"Most pertinent of all, were concerns raised in relation to poor infection control measures which resulted in staff being required to change in the toilets, in addition to a significant amount of equipment being stored in the isolation room.
"The CHC would consider this as inappropriate."
The health board has plans to relocate the unit within the hospital, he added.