Police in North Carolina have released the body cam footage of the moment an officer shot dead a woman coming at him with a butcher's knife in an effort to show the shooting was justified.

Chieu Di Thi Vo, 46, was shot and killed by a police officer on March 25, 2014, after police were called to a fight at an apartment complex in Greensboro.

Vo, who was born in Vietnam and did not speak English, was having an argument with her mother and was shouting in Vietnamese when cops arrived.

Police say she came at the officer with a meat cleaver and refused orders to drop the weapon when he opened fire, Fox 8 News reported.

Disturbing video: This is the moment that Chieu Vo, 46, was shot dead by an officer responding to reports of a fight between Vo and her mother at an apartment complex in Greensboro, North Carolina, in March 2014

Vo, who did not speak English and had bipolar disorder, was shot several times and is seen falling to the ground, with the meat cleaver in her hand, in the body cam footage

The footage shows the woman collapse to the ground screaming in pain after being shot about four times

At the end of the clip, the officer goes over to Vo, who is now on her back. Her family say police unnecessarily used deadly force

The disturbing video was released at the request of the Vo family, who maintain police acted improperly and did not need to fatally shoot Vo, who suffered from bipolar disorder.

A witness who called 911 can be heard saying that Vo was chasing her mother around the grounds of Aberdeen Townhomes with a knife.

Capt. Mike Richey says the blade was eight inches.

The body cam footage of officer Tim Bloch shows him asking people the whereabouts of Vo as the video starts.

The video captures the officer screaming, 'put it down', before firing several rounds.

Vo stops for a second before falling to the ground, screaming.

Both Bloch and his captain said the use of deadly force was necessary.

'My training took over and it's what probably saved my life,' Bloch told Fox 8 News.

Officer Tim Bloch (right), the cop who shot dead Chieu Vo (left), was cleared of any wrongdoing at the time of the shooting and has since left the force

'We have serious concerns about the process in which the city has taken on to release the video,' Executive Director of the Southeast Asian Coalition Cat Bao Le said

Bloch was cleared of any wrongdoing by law enforcement investigations and left the force in 2014.

He claims the video does not show him giving Vo CPR after the shooting.

Captain Scott said the shooting incident lasted for about six seconds. Vo died in hospital two days later.

'It was a tragedy for the police department, the Vo family and this community,' Scott said.

However Vo's family say it is unacceptable how the case has been handled, particularly that it took two years for the video to be released publicly.

'We have serious concerns about the process in which the city has taken on to release the video,' Executive Director of Southeast Asian Coalition Cat Bao Le told Fox.