fifties are being treated in hospital

A man in his forties and a man in his

A total of five water cooling towers in the same area of Sydney have tested positive for a potentially deadly bacteria after two more people contracted Legionnaires' disease.

NSW Health said five cooling towers in central Sydney on Margaret, Kent, King and George Streets tested positive for Legionella on Tuesday following an inspection of 89 sites across the city.

They also confirmed that two more members of the public have contracted the potentially fatal respiratory infection.

A total of five water cooling towers in central Sydney - on Margaret, Kent, King and George Streets - have tested positive for a potentially deadly bacteria after two more people contracted Legionnaires' disease

Dr Vicky Sheppeard, director of NSW Health Communicable Diseases Branch, said the towers had been 'cleaned and disinfected'.

A man in his forties and a man in his fifties, who frequented the city about the same time as the three other confirmed patients, are being treated in hospital.

Dr Sheppeard said one of the men was in the intensive care unit and the other was in a stable condition.

She said Legionella bacteria flourished in water cooling towers and that was why the NSW Health Department had 'specific regulations to prevent... this type of occurrence'.

Dr Sheppeard added the warm weather could be contributing to the bacteria outbreak.

'Potentially it can be related to the very long, warm period that we've had that has required ongoing operation of cooling towers, there may be other factors and we have an expert group looking into that question ,' Dr Sheppeard said.

NSW Health said five cooling towers in central Sydney on Margaret, Kent, King and George Streets tested positive for Legionella (pictured is a stock image) following an inspection of 89 sites across the city

An elderly man and two women - who all work around Wynyard train station (stock image) - have fallen ill since ANZAC Day

The three original patients, a man in his eighties and two women in their thirties, fell ill after Anzac Day and all work near Wynyard train station.

One has been discharged from hospital, another is stable and the third remains in a critical condition.

Legionnaires' disease is a type of pneumonia caused by a bacterial infection of the lungs that can develop after someone breathes contaminated water vapour or dust.

A City of Sydney spokesperson told Daily Mail Australia: 'As public health is our number one concern, we are taking the matter very seriously, and providing every assistance to NSW Health who are leading the investigation.

'The city will continue to provide the community with information about the issue as it becomes available.'

Tens of thousands of commuters pass through the suspected infection area each day, and it is also a focal point for tourists.

The cooling towers were inspected as outbreaks are often associated with contaminated air conditioning systems in large buildings.

The spokesperson said: 'Under the Public Health Act, the City maintains a register of air conditioning towers and who is responsible for their maintenance.'

The latest outbreak comes after a man aged in his 80s died in March after contracting the disease near the Town Hall area.