Boom or bust! A bizarre bomb scare had Nelson police evacuating homes after an explosive device resembling a bra was found in a house in Stoke.

The explosive bra was later discovered to be one of the more volatile entrants in last year's Wearable Art bizarre bra section.

Sergeant John Price of Stoke said police heard about the possible booby trap after a concerned woman rang the station.

Her son had found the device in an abandoned car and taken it home.

Nelson explosive expert John Herd was called to the scene while police evacuated three properties in the area.

It took Mr Herd 10 minutes to get abreast of the situation and realise the device, which looked "theatrical" and featured wires and tubes coming from a wooden box, was not a threat.

"It had two domes with 'bomb' written on it," he said

Mr Herd said it was "a real laugh" once he realised what had happened, but till then the matter had been treated seriously.

Wearable Art director Suzie Moncrieff said the bra was an entry in last year's event and had been worn with sparklers ad an illuminated countdown device,

"I just couldn't believe it when I heard. I just had to laugh and laugh," se said. -- NZPA