"The defendant has taken a couple of steps and swung a heavy punch flush onto the victim's lower jaw and face area, causing the victim to stumble backwards."
The victim appeared to stumble out of his cell, as CCTV footage was able to capture what happened next.
"The defendant then continued to throw a further 15 plus punches to the victim's head and as the victim attempted to evacuate himself, he was followed by five other inmates.
"He was followed into his cell area. It's unknown what happened inside the cells as it was out of the CCTV system.
"After approximately 60 seconds the defendant and five others came out of the cell, followed by the victim who was bleeding out of his face."
Prison staff noticed the victim's injuries and he was taken to hospital with suspected fractures, cuts and bruising to his lips, jaw and cheek.
Heke was sentenced to six months' imprisonment by Judge Chris Sygrove in New Plymouth District Court having pleaded guilty to common assault.
He was also convicted on charges of refusing to give a blood sample, resisting police, intentionally obstructing police, failing to stop for police, breaching release conditions and recklessly operating a motor vehicle.
In 2016, Heke led New Plymouth Police on a 20 minute pursuit when he drove dangerously towards Waitara in a stolen ute.
The ute was stopped after police laid road spikes and they discovered Heke was drunk when they apprehended him.
Judge Sygrove said Heke's driving on this occasion was outrageous.
"You continued driving on the wrong side of the road, in the dark at high speed even after one of your tyres had been spiked by the police.
"Then, when the police finally caught up with you, you obstructed them and refused to accompany them."
Last year, Heke was sentenced to 18 months' imprisonment for his part in destroying stolen vehicles by doing burnouts in them.
He was serving this sentence at the time of the assault in August.
"The assault on your fellow inmate was a bit of a cowardly act because not only did you punch the victim, but then you and five mates went into the cell and dealt to him," Judge Sygrove said.
"Six on one is a bit gutless in my view."
On September 4 when Heke appeared in Whanganui District Court, the Chronicle published a report calling for urgent action in Whanganui Prison from chief ombudsman Peter Boshier.
"I consider there is a clear and urgent need for the prison to address the levels of violence and intimidation," Boshier said.
"Prisoners fear for their safety so they don't report the stand-over tactics or bullying they experience from other inmates, yet they tell my inspectors that these are common occurrences."
Inspectors made an unannounced inspection at the prison in February and found there was a high number of violent incidents each month and these had been increasing.
Two of the prison's units had the highest number of recorded assaults of all the Department of Corrections' lower north region facilities.
