Qld AG appeals Cole Miller death sentence

The man who killed promising teenage sportsman Cole Miller should have his jail term increased to 12 years, a court has heard.

Lawyers for Attorney-General Yvette D'Ath on Wednesday argued in the Court of Appeal that the seven-year sentence given to Armstrong Renata for the single-punch death in 2016 was inadequate.

Mr Miller was struck from behind by Renata while on a night out in the Fortitude Valley nightclub district.

The 18-year-old suffered a massive brain trauma and his family made the heartbreaking decision to turn off his life support two days later.

"What we have here is bordering on the worst example of that type of offence ... here the starting point needs to be something that resembles ... that maximum penalty," barrister Carl Heaton QC said.

Under his current sentence Renata, 23, who pleaded guilty to a single count of unlawful striking causing death, will be able to apply for parole in less than four years.

Mr Heaton argued in court that Justice Helen Bowskill had erred by using manslaughter cases as a guide in setting Renata's sentence.

He said the offence of unlawful striking causing death was more serious, and deserved a harsher punishment.

A 12-year sentence would require Renata to serve 80 per cent of this time behind bars before he can apply for parole.

Defence lawyer John Allen QC said it would be "unusual" to approach the sentence by working down from the maximum penalty, and that this was not justified in Renata's case.

The court has reserved its judgment.