NSW Police have brought in the homicide squad amid fears the 95-year-old great-grandmother with dementia who was tasered by an officer will die of her injuries.

The job of the senior constable involved in the stun gun use is also under review.

Clare Nowland is fighting for her life in hospital after staff at her NSW nursing home called the police on Wednesday morning, when Mrs Nowland was armed with a steak knife.

Officers reportedly struggled to disarm her before one pulled out their stun gun and fired as Mrs Nowland stood next to her walking frame.

“One of the police officers who responded, a senior constable, activated his Taser, which struck Claire, whereby she fell to the ground, striking her head,” southern region commander Assistant Commissioner Peter Cotter said on Friday.

“At the time she was Tasered she was approaching police. It is fair to say at a slow pace. She had a walking frame. But she had a knife.”

Mrs Nowland, a great-grandmother who was well known in the local community and is believed to have been at Yallambee Lodge near Cooma for about five years, sustained critical injuries.

“Immediate medical care and attention was delivered by the nursing staff and the paramedics and also the officers involved. As a result of … the injury to her head, she was taken to the district hospital, which is where she remains today. It is equally fair to say that she is in a state of ill health,” Mr Cotter said.

He refused to give more details about Mrs Nowland’s health status or prognosis, “except to say that she remains in a critical condition and her family and extended family surround her and have done since about midday on Wednesday”.

“There are significant concerns clearly for her health and where that may lead,” he said.

“We feel for all her family, we have been in contact on the ground there at Cooma with our officers, our senior police who have been with the family and been equally at the bedside of Clare since Wednesday.”

Mr Cotter said Mrs Nowland’s family had asked for privacy, amid reports earlier that she is not expected to survive her injuries.

“What they have asked of us is to express on behalf of them that if they could be left alone to attend to their mother, grandmother, and the health of the family and the sadness they feel at this stage is the main concern,” he said.

NSW Police have begun a level one critical incident investigation into Mrs Nowland’s tasering. The criteria for a level one classification is an injury that leads to death or imminent death, which is why the homicide squad is also involved.

The incident was captured by the officers’ body-worn cameras, and footage is being reviewed by police. Mr Cotter said the footage was “confronting”.

The officer involved had 12 years experience.

NSW Council for Civil Liberties president Josh Pallas said police shouldn’t use tasers on vulnerable people who were experiencing dementia or a mental health crisis.

“Surely, there must be more appropriate ways to deal with non-compliant people who are suffering,” he said.

According to NSW Police guidelines, an officer can use a stun gun when violent resistance is occurring or is imminent or when an officer is in danger of being overpowered.

The Snowy Monaro Regional Council, which runs Yallambee Lodge, said staff had followed procedure.

“Council are supporting our staff, residents, and families during this difficult time,” the council said in a statement.

Yallambee Lodge is a 40-bed facility designed for people who can no longer look after themselves in their own homes, according to the council’s website.

Mrs Nowland’s family, who have asked for privacy, are believed to be at her bedside.

Mrs Nowland made headlines in 2008 after skydiving for her 80th birthday and the footage was aired on the ABC.

-with AAP