Sydney’s top hospital and the NSW Government are in crisis mode after being forced to admit that lethal mould has killed three patients and made four others seriously ill.

7NEWS can reveal attempts to cover up the health disaster at Royal Prince Alfred Hospital in Sydney’s inner-city suburb of Camperdown and expose appalling hygiene levels in hospitals right across the state.

“We have tested, we have cleaned, we have changed air vents,” Sydney Local Health District’s Deb Willcox said.

“The cluster is six patients between October and December. Two of those six patients have subsequently passed away.”

But highly sensitive health documents obtained by 7NEWS reveal three deaths and seven cases in total from the deadly outbreak inside RPA Hospital’s ward nine, where organ transplant patients were receiving life-saving treatment between October and December last year.

All three patients who died passed away within a month of diagnosis.

Concerns were first raised in December, with the Chief Health Officer establishing a crisis panel on Christmas Eve.

Images show mould inside the ward.Images show mould inside the ward. Credit: 7NEWS Three organ transplant patients died, the report shows.Three organ transplant patients died, the report shows. Credit: 7NEWS The health district claims the hospital is now up to scratch.The health district claims the hospital is now up to scratch. Credit: 7NEWS

A secret media statement was drafted in case questions were asked, with no mention of any deaths.

“This is a cover-up, plain and simple, and heads need to roll,” shadow health minister Sarah Mitchell said.

“The government was hoping that nobody would find out about this news.”

The cluster has been linked to Aspergillus spores whipped up by nearby construction work. Confidential testing reports show air monitors were moved in and extensive cleaning undertaken.

Health authorities now insist the hospital is safe.

“Right now, I can categorically say that the air in RPA is cleaner than the air outside,” Willcox said.

NSW Health has been battling mould at hospitals across the state.NSW Health has been battling mould at hospitals across the state. Credit: 7NEWS Mould in intensive care in Wollongong.Mould in intensive care in Wollongong. Credit: 7NEWS Mould in the paediatric unit at John Hunter Hospital.Mould in the paediatric unit at John Hunter Hospital. Credit: 7NEWS

But 7NEWS can reveal health authorities have been quietly battling mould at hospitals across the state.

Mould has been found in day surgeries at Ryde, in intensive care at Wollongong, and in the paediatric unit at John Hunter Hospital.

At Wyong Hospital, infection concerns were so severe they ripped up and replaced the floor.

The transplant ward at RPA reopened on February 9, with health authorities declaring it safe.

But the opposition is calling on the government to come clean on the filth they’ve found inside NSW hospitals.