Radio New Zealand - Te Reo Irirangi o Aotearoa

A New Zealand heritage group says it has discovered what appears to be a German U-Boat lying in a watery grave off the Kaipara Coast in Northland.

The Underwater Heritage Group says the mystery of how the U-boat came to be there involves Nazis and stolen treasure.

The group's vice-president, Noel Hilliam, believes the submarine is U-196 and that it sailed to New Zealand in 1944.

Mr Hilliam claims the U-boat was used to smuggle 13 high-ranking Nazis onto Northland soil, where they assumed identities as Austrians.

He says the story has now come to light because the descendants of one of the men want to find stolen treasure the group brought with them and repatriate it to Germany.

Mr Hilliam says the sunken boat has been observed seven times and three divers have been on it, but its identity as U-196 is only speculation.

He hopes divers can go onto the wrecked submarine early next year to take photographs, proving it is a U-boat.

The location of the treasure he says the Nazis brought with them remains unknown.