Police are searching for information about a firearm recovered during their investigation into the death of Rau Tongia.
The 33-year-old was killed in the Wellington suburb of Karori in December last year.
Police believe the long-barrelled Breda Brescia semi-automatic shotgun may have been stolen, and they would like to find its legal owner.
It has detailed engravings and 'Sportco' printed on the base of the stock.
A 35-year-old woman has been charged with the murder of Tongia.