A Hungarian tourist who killed a man with a banjo has had his appeal for a lighter sentence dismissed.

The Court of Appeal agreed the trial judge that Ferdinand Ambach's manslaughter conviction was "close to the murder end of the scale".

Ambach was jailed in 2009 for 12 years with a minimum non-parole period of eight years for killing 69-year-old Ronald Brown by beating him with a banjo and then putting its broken neck into his mouth.

Ambach appealed his sentence on the basis it was excessive, arguing he would have pleaded guilty to manslaughter had he been given the opportunity and that his culpability was less than what was ruled in the trial.

He explained his lack of emotion throughout the proceeding as reflecting his lawyer's instructions not to react.

He further submitted that because he would be deported to Hungary on his release, the imposed minimum period of imprisonment (MPI) was not necessary.

But the Court of Appeal agreed with Justice Helen Winkelman's decision and dismissed the appeal.

"We consider no issue can be taken with the starting point adopted by Winkelmann J. Essentially, as the judge said, this was a cruel and brutal crime," Justice Ellen France said in the judgment.

"We see no basis for interfering with the judge's assessment that the extreme violence involved called for strong denunciation. An MPI was appropriate to meet that purpose."

Ambach, a dive master in Hungary, met Mr Brown at a bar in the Auckland suburb of Onehunga before heading to Mr Brown's home where Ambach claims he lost control after being subjected to sexual advances and a spiked drink.

Mr Brown died in hospital three days later after his life support system was switched off.