A bomb scare has closed part of Auckland International Airport after a passenger arrived with what is believed to be a World War II relic that is feared to still be live.

The man is believed to have carried a mortar shell in his hand luggage, which he collected as a souvenir on a diving trip, a Customs spokeswoman said.

He declared the mortar shell to Customs and police were then notified.

The bomb squad is investigating the relic and the ambulance has been put on alert.


Part of the airport has been cordoned off after the man arrived shortly after midday with the "suspicious article", airport spokesman Richard Llewellyn said.

"The process of assessment of that suspicious article is underway," Mr Llewellyn said.

Part of Customs has been closed and it has slowed the processing of arriving passengers, Mr Llewellyn said.

A spokeswoman said the ambulance had been alerted but were "not responding at this stage".

Mr Llewellyn said so far the security scare had not affected any other flights.

"It has slowed the processing of arrivals but it hasn't closed [arrivals]. One of the lines has been cordoned off [and] the number of processing staff has been reduced," Mr Llewellyn said.

"We do ask people to be patient and I'm sure police and Customs will go through their processes as quickly as possible."