A NSW woman shot in the chest with a bean-bag round during an attempted arrest died after it entered her body, striking her heart.
The incident has prompted NSW Police to temporarily halt the use of the usually non-lethal weapon while the force conducts a review.
Krista Kach died in hospital on Thursday after barricading herself in her unit and allegedly threatening people, including police officers, with an axe in Newcastle in northern NSW.
After a nine-hour stand-off, police gained access to the unit and deployed a Taser, as well as the bean-bag round, while attempting an arrest.
The 47-year-old, who was hit in the shoulder area was able to walk to a nearby ambulance, which took her to John Hunter Hospital where she later died.
Acting Commissioner David Hudson on Tuesday said the cause of her death was "a gunshot wound to the chest".
"It would appear that the bean-bag round ... has entered the body of the deceased and ended up striking her heart, causing her death," he said.
"It was not intended to be a fatal outcome for the person."
Mr Hudson said police would temporarily suspend the use of bean-bag rounds, which had been deployed 15 times in the state this year without incident.
"That suspension will remain in place until we do a full review of the capability and see if it is worth continuing," he said.
"It is a less than lethal option or so (it is) defined, and if we remove it permanently from our capability, we will only be left with Tasers between a baton and a firearm, and that's a concern to us.
"But we need to make sure that when we deploy a less-than-lethal option, it has to be less than lethal."
Bean-bag rounds are small fabric bags filled with shot or another heavy material that fan out when they are fired from a gun.
They are meant to create a kinetic impact on the body that immobilises the target but can, depending on what part of the body they strike, cause serious injuries.
The review will investigate if any particular batches of rounds were flawed, alternative methods to bean-bag rounds and police involvement in mental health call-outs.
NSW Police Minister Yasmin Catley has backed the police force while awaiting the findings of three investigations into the incident.
Ms Kach's grieving family has not yet responded to the latest information from police.
In a statement on Monday, they condemned the police response, saying Ms Kach was distressed after being told she would be evicted from her unit.
"What happened on Thursday was a disturbing and heartbreaking response by the police to a vulnerable person that had been told that she would soon be homeless," the family said in a statement.
Ms Kach's death is also the second fatal incident involving NSW Police using a stun gun in recent months.
Clare Nowland, 95, died after being Tasered at a Cooma nursing home in May.
