An international traveller packed a loaded handgun in his luggage and got it into Auckland Airport.

The Bauer .25-calibre gun was found after he had collected his luggage and put it through a Ministry of Agriculture and Forestry x-ray machine as he prepared to leave the airport.

The passenger, Baptiste Julien Jeune, 69, had arrived on a flight from Tahiti, and had been cleared by New Zealand Customs officers.

The MAF officer who discovered it while x-raying the bag for biosecurity reasons said he was "shocked" and "alarmed".

The handgun had a loaded magazine in it and a round in the chamber. Another loaded magazine was also in his bag which was stowed in the plane.

Jeune, who arrived from Faa's International Airport in Papeete, was arrested and appeared in the Manukau District Court the following day. The incident happened in January. He was fined $1500 for unlawfully importing a firearm.

Civil Aviation Authority spokesman Bill Sommer said the gun was in stowed baggage so was not an aviation security issue. However, the matter is recorded on a Civil Aviation incident report released to the Herald on Sunday.

Sommer did not think airport authorities in Tahiti would have necessarily been screening for weapons. But he couldn't say why it would not have been picked up on an x-ray machine before Auckland.

"Anyone can go to an airport with a loaded gun in their pocket and no one would know. It only becomes a problem if they take it on board and can use it on a plane," he said.

Auckland Airport spokesman Richard Llewellyn would not comment on security matters.

Aviation security services Avsec chief executive Mark Everitt did not return calls.

Auckland Airport police Senior Sergeant Graeme Fleming would say only " a man who came through from Tahiti into New Zealand was intercepted at the border with a loaded hand gun. The firearm has been destroyed. There was a police prosecution and the matter is closed".

The French Embassy told the Herald on Sunday it had not been informed by New Zealand authorities that a French national had been arrested for a firearms offence.

Air Tahiti Nui spokesman Tony Harrington said the airline had no record of being informed by New Zealand authorities of the incident.

Air New Zealand spokesman Mark Street wouldn't comment.

"Airlines don't control security, the French authorities do. We don't discuss security matters certainly when they are not in our control," he said.

MAF spokesman Matthew Thorpe said it was pleasing to find the firearm.

"It was the last stop before leaving the airport. He had cleared Customs. Usually Customs find things like that. I don't know why he wasn't x-rayed at the other end [Tahiti]," he said.

Customs Minister Maurice Williamson and associate Transport Minister Nathan Guy, who has responsibility for aviation, wouldn't comment.