Now police are appealing to the public for information on the weapon, which they believe is a .22 calibre.
On Monday night, police were contacted by a concerned member of the public who had been shown the pistol by a man in the Dunedin wharf area.
While they were interviewing the informant, " a car of interest" - a white sedan - with a male and female occupant drove past and was pulled over by armed police in Fryatt St, Constable J Wagstaff said.
A search of the Dunedin man revealed he had possession of the pistol, and he was charged with unlawful possession of a firearm.
The 47-year-old man appeared in front of justices of the peace at the Dunedin District Court yesterday and was bailed to appear later this month.
Const Wagstaff said the pistol was not stamped with a make, and appeared to be home-made by someone "gifted at engineering".
"This works completely. If I was to load this now, you would not want to be in front of it." The man remained tight-lipped about where he sourced the pistol from, he said.
Anyone with information was urged to contact Dunedin police on (03) 471-4800.
