About 1.15pm Wednesday police were called to a home on Robertson Street after concerns were raised for the welfare of a man at the property.

On arrival, officers from Manning-Great Lakes Police District attempted to speak with a 40-year-old man, believed to be armed with a knife.

He remained inside the house for a number of hours, while police negotiators attempted to speak with him.

Just after 10.15pm, specialist tactical police forced open the door of the house and were challenged by the man, who police said was armed with a large knife.

Officers deployed a taser and other tactical options, which were ineffective, before the man was shot.

Paramedics treated the man at the scene before taking him to Manning Base Hospital, where he died a short time later.

A critical incident investigation team from the homicide squad will now investigate the circumstances surrounding the incident.

The investigation will be subject to independent review.

All information will be provided to the coroner who will determine the cause of death and make any findings about the events leading to the shooting.

A crime scene has been established at the location, which will be examined by specialist forensic officers.

No further details are available at this time; however, police are appealing for witnesses to come forward.

Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au.

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