A person has died after contracting legionnaires' disease at Burwood, in Sydney's inner-west, the New South Wales Health Department has confirmed.

Three people have fallen ill in the area in the past week or so, health authorities said.

Director of Public Health Dr Leena Gupta said the person died last week, and two other people had also been affected.

"One patient unfortunately has passed away, another patient has been discharged, and another patient is still in hospital," she said.

"These three cases are not related to the CBD outbreak. This afternoon we found a small case, all of which have been in the Burwood area."

Dr Gupta said health authorities and Burwood Council were investigating all the cooling towers in the area, as the disease is associated with contaminated air-conditioning systems.

It follows an outbreak in Sydney's CBD earlier this month in which five cases were confirmed by health authorities.

The death is the second legionnaires' fatality in NSW this year —a man aged in his 80s died in March after contracting the disease in the CBD.

Legionnaires' disease is an infection of the lungs caused by bacteria of the Legionella family and usually causes fever, chills, a cough and shortness of breath.

People can be exposed to the bacteria when a water cooling tower — which is often located on a building's roof — emits contaminated water vapour into the air that can then drift down onto the outside street.

Meanwhile, the New South Wales Opposition has renewed a call for a taskforce made up of experts in communicable diseases to help mitigate the outbreaks.

Shadow health spokesman Walt Secord proposed the taskforce be comprised of NSW Health, communicable disease researchers, and climate change experts and local government.

"The community must be confident that the Government is taking all necessary steps to protect the community," Mr Secord said.

"The State Government is not doing enough.

"I am willing to offer bipartisan support and work with the Government to improve the current laws and the current regulatory regime that surrounds legionnaires'."

NSW Health announced last week that the department had a Legionella working group of experts which was reviewing the recent outbreaks and considering whether any new measures were needed to help strengthen the current prevention and control procedures.

NSW Health Minister Jillian Skinner has been contacted for comment.