A 36-year-old man Bega man has been arrested and charged with murder after allegedly stabbing to death a 49-year-old man in Eden after what police said was a possible disturbance between two men.

According to police they arrived on the scene just after 3pm, and as inquiries continued and officers entered the home on Moorhead St they found the injured man who later died at the scene.

It was soon announced a Critical Incident Investigation Team from the Lake Illawarra Police District, assisted by State Crime Command's Homicide Squad will continue to investigate the circumstances surrounding the incident.

Police have said the investigation is subject to independent review and 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 man's death".

According to NSW Police's public documentation, a Critical Incident Investigation Team is called for level 2 critical incidents, which could include anything from the death or serious injury of a person in police custody to the attempted homicide of a police officer, or even the death or serious injury to a person arising from a police operation.

A critical incident may also be any other incident that a region commander considers could attract significant attention, interest or criticism, such that the public interest will be best served by investigating the matter under the Critical Incident Guidelines.

"The team should examine the lawfulness of police action, the extent of police compliance with relevant guidelines, legislation and internal policy and procedures," the Professional Standards Command's Critical Incident Guidelines public document states.

The Homicide Squad must provide specialist investigative advice for the duration of the investigation, which will be independently monitored and reviewed by the Professional Standards Command.

The region commander is responsible for determining whether an incident is a critical incident and at its conclusion provide a comprehensive report to the Deputy Commissioner of Field Operations.

The incident team is required to conduct a full investigation of the incident including relevant events and activities leading to the incident, and the Senior Critical Incident Investigator is responsible for gathering the necessary evidence and for determining the degree of an officer's involvement in an incident.

If the incident involves a death the senior investigator will liaise, via the duty operations inspector, with the on duty State or Deputy State Coroner.

Officers will be interviewed during the investigation whether or not there is any suggestion of misconduct, and can choose to exercise their right to silence, and object to answering questions if they feel they could incriminate themselves.

Civilian witnesses are also interviewed, and if charges are to be laid, a brief of evidence from the senior investigator will be sent to the Director of Public Prosecutions.

The Coroner must then be told indictable charges have been laid, and will review the brief, and must conduct an inquest regardless of whether the brief of evidence goes to the DPP.

The Professional Standards Command then choose a review officer who monitors and reviews the "probity and transparency of the investigation".

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