One-punch killer's sentencing delayed amid prison assault allegations

A New Zealand man who faces a hefty sentence for killing Brisbane teenager Cole Miller with a one-punch strike has had his sentencing postponed amid fresh assault allegations.

Armstrong Renata was due to be sentenced in the Brisbane Supreme Court on Monday for unlawful striking causing death after pleading guilty last year.

The 22-year-old punched Mr Miller while out in the Fortitude Valley nightclub district on January 2, 2016.

The 18-year-old was an elite water polo player and on track to follow in the footsteps of his Olympian brother, Billy.

Cole Miller. Source: Supplied.

But he suffered massive brain trauma from the attack, with his family making the heartbreaking decision to turn off his life support in hospital the following day.

Renata was charged under tough new laws introduced in Queensland in 2014 designed to combat alcohol-fuelled violence.

On Monday he was escorted into the dock in handcuffs flanked by an unusually high number of security guards.

The court heard he had been charged with two counts of serious assault in April 2017, later confirmed by solicitor Adam Magill to have been against corrective service officers.

Renata faces allegations of assault against prison guards. Source: Facebook

Renata's case was adjourned to July 21 for review.

"He's all right, his family have asked me not to comment," Mr Magill said outside court.

Renata faces a maximum sentence of life imprisonment and will have to serve 80 per cent or 15 years of any jail sentence handed to him.