The health minister has said he thought there had been a mistake when he saw the cost of the new maternity hospital written down for him.

The Belfast hospital is already 10 years behind schedule after numerous delays.

Last month, BBC News NI revealed that a potentially dangerous bacterium was discovered in the facility's water pipes just weeks after it was officially handed over to the Belfast Health Trust by the contractor.

In July, it was reported that high levels of the bug Pseudomonas (PsA) had been discovered and that the opening of the site could face significant delays.

The trust said it cannot give a new projected opening date as an independent review is under way.

Repairs to the building are expected to run to several million pounds.

Answering questions in the assembly on Tuesday, Mike Nesbitt said the costs of the project were staggering.

Giving an update to assembly members, the minister said it was "a very serious problem and it may take a very long time to fix".

"The hospital has been subject to delay after delay, year after year after year, and the consequence of that is that the price... the cost of building the hospital is now eye-watering," he said.

"When I first saw it written down on a piece of paper I thought there had been a typographical error - it is phenomenally expensive.

"Having to spend the money to fix the PsA issue, particularly if the costs fall to the Trust, is going to put even more pressure on an increasingly pressurised budget."

Pseudomonas does not usually affect healthy people, but infants and people with weakened immune systems are vulnerable.