A tourist who killed a man with a banjo after he received unwanted sexual advances has been found guilty of manslaughter.

Ferdinand Ambach, a Hungarian tourist, was drinking with Ronald James Brown, on December 7, 2007, at a suburban Auckland bar before they went to Mr Brown's Onehunga flat.

A violent argument erupted and Mr Brown, 69, was bashed repeatedly with a banjo before the neck of the instrument was rammed down his throat.

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

The defence case was that the 31-year-old accused was provoked by two unwanted sexual advances by Mr Brown, who was gay, and that attention, and the effects his drink being spiked, caused him to act in an involuntary way where he wasn't in control of his actions.

The Crown said Mr Brown was struck five times before Ambach rammed the broken-off neck of the banjo down his throat.

When police arrived at the scene, they found Mr Brown badly injured and Ambach throwing furniture through an upstairs window and on to the lawn, while yelling in Hungarian.

Ambach told police that he could only remember parts of what happened that night.

Summing up the case, Judge Helen Winkelmann said they should put aside any prejudices they may have about homosexuality.

"Mr Brown was a homosexual but he kept his sexuality separate from his friends and family. That doesn't make it blameworthy.

"You have to reach your verdicts based on what you've heard," she said.

The jury was told they had to agree on three areas - that there had been a homicide, that it was a culpable homicide and that the accused had murderous intent.

Judge Winkelmann added that the jury had to consider how Ambach reacted before and after the attack, and whether he was provoked by sexual advances from Mr Brown.

They were also told to consider whether these advances caused Ambach to lose the power of self control.

- with NZPA