A New Zealander who set up a company linked to an airliner loaded with North Korean arms and detained in Bangkok says he doesn't know anything about the matter.

Michael Taylor, of Amberley in North Canterbury, acknowledged setting up Auckland-based company, SP Trading Ltd - to whom the plane was leased - but said he had no knowledge of the aircraft or its contents, the Wall Street Journal reported.

"We don't know anything about that matter. I basically do incorporation services for clients," said Taylor.

He said he had set up about 2000 companies and this was the first time something like this had happened.

"We don't have a stash of weapons here, that's for sure," he told the newspaper.

The plane, registered to a carrier in the Republic of Georgia, was detained in Thailand last week carrying missiles, explosives and other armaments from North Korea.

Its planned destination was unknown.

The five crew members, from Belarus and Kazakhstan, have been detained in Thailand and deny knowing about the weapons.

Officials in Kazakhstan and Georgia said the aircraft was leased to SP Trading, an Auckland company that lists Lu Zhang as director.

The company Taylor set up goes by the same name and also lists Lu Zhang as director.

Taylor told the Wall Street Journal he had no information about Zhang because he only did "the incorporation of the company".

SP Trading lists as its address the office of a company called GT Group. GT Group was preparing to make a statement on the matter, Taylor said.

New Zealand police and the Ministry of Foreign Affairs and Trade are investigating.

The Wall Street Journal said New Zealand promoted itself as an easy place to set up businesses.

But critics say the rules governing the creation of companies, which don't require proof of identity or the registering of a residential address, are too lax and can lead to abuse.

"It's very easy to set up here in New Zealand and there have been lots of fraudsters who have set up here because it has a safe and clean and honest image," Alex Tan, a specialist in fraud investigation at the Auckland office of PricewaterhouseCoopers, told the Wall Street Journal.