Wellington  - A Hungarian tourist killed a 69-year-old gay man he met in a bar by beating him with a banjo and ramming the handle down his throat, police alleged when his murder trial opened in Auckland on Monday.

Ferdinand Ambach, 32, a dive master, pleaded not guilty in the Auckland High Court to murdering Ronald James Brown in December 2007.

Prosecutor Nick Williams told the court that Ambach had been in New Zealand a month when the pair met in a bar before going back to Brown's flat in the Auckland suburb of Onehunga, the New Zealand Herald reported on its website.

He said a violent argument erupted after a misunderstanding occurred between the men, with Brown apparently wrongly assuming that Ambach was gay.

Police called by a neighbour arrived to find Brown badly injured and Ambach screaming in Hungarian and throwing furniture through an upstairs window. Brown died in hospital three days later.

Interviewed by police, Ambach said he could remember only parts of what happened that night.

The trial before a jury is expected to last three weeks. (dpa)