Corroded 'mortar bomb' shock for Dunedin hospice shop

Police had to cordon off part of State Highway One in Dunedin after as they dealt with the bomb scare. Photo / ODT

A box containing an old train set - and what was believed to be a corroded mortar bomb - triggered a major police callout in central Dunedin.

The drama ended when the ordnance - later identified as a smoke bomb from the 1970s - was removed and detonated at a safe place by the Burnham-based New Zealand Defence Force bomb disposal unit.

Dunedin Hospice Shop manager Cat Callanan was sorting through recycled metal when she came across a ''lovely old train set'' in a box yesterday.

She also found a corroded item, shaped like a bomb, which she picked up to show another staff member.

She carried the ''leaking item'' to volunteer John Vickerstaff, who shouted at her: ''Holy hell, that's a bomb. Get everyone out of the building.''

Mr Vickerstaff said, as a child, he had played with souvenirs from World War II and ''usually they were safe''.

''With this one, it was too hard to tell. I knew what it was and just didn't like the look of it.''

Police evacuated and cordoned off several Bond St buildings, and temporarily diverted traffic away from State Highway 1 between Jervois and Rattray Sts.

At the scene, Sergeant Steve Aitken said the cordon and traffic diversions were necessary as police were unsure what they were dealing with.

The ordnance was in a ''fairly corrosive state and we are unsure whether it is alive or inert''.

Yesterday afternoon, police tracked down the person who had donated the train set in good faith. The person believed the ordnance was a smoke round.

Sgt Aitken praised the charity shop staff for contacting police.