Auckland Airport is back to normal after a passenger declared a pair of World War II artillery shells.

The Defence Force bomb squad and staff from Fire and Emergency were called to the international arrivals hall just after 10pm on Thursday night.

"Plane full of people arrives at immigration in #aucklandairport to be told we face a two hour wait because immigration has been closed because of an incident. Sounds worrying," wrote UK author Jamie Goode, who'd just arrived on a 787 Dreamliner.

Passengers faced a two-hour wait to get through Customs, Stuff reported. There was no disruption to outbound traffic.

The Defence Force told Newshub the passenger was inbound from Vanuatu.

The shells were confiscated. Police aren't planning to prosecute.

Newshub.