Bottled water is said to be stockpiled in the basement of the Royal Hospital for Children in Glasgow, part of the Queen Elizabeth University Campus.
The hospitals, run by NHS Greater Glasgow and Clyde, are subject to scrutiny after the deaths of two patients infected with Cryptoccocus infection, linked to pigeon droppings.
One of those who died was a ten-year-old boy being treated in the adult hospital, while the other was an elderly woman.
Last year, Scottish Water and Health Protection Scotland were called into the children’s hospital and UK experts were consulted after six children developed infections linked to bacteria in the water supply.
Paediatric patients being treated for cancer were transferred into the adult hospital after the problem emerged in March, and were treated with antibiotics.
The health board carried out a raft of improvements at the hospital, including replacing taps and shower heads and fitting water filters and is now spending £1.25million upgrading the ventilation system in one area of the children’s hospital.
A hospital source told the Evening Times: “We’ve been told not to drink the water and supplied with bottled water.
“If you go into the basement of the hospital, there are pallets and pallets of bottled water.
“We have enough bottles to last a year.
“Over the last few weeks they must have upped the amount of chlorine in the tap water as every time you turn on the taps the smell is really strong.”
Two other patients are being treated for a separate fungal infection - Mucor - with one described as seriously ill.
Regarding the tap water ban, a spokesman for NHS Greater Glasgow and Clyde said: “The cabinet secretary has announced a review into the design, commissioning, construction and maintenance of the Queen Elizabeth University Hospital.”