New Zealand's National Institute of Water and Atmospheric Research (Niwa) ship Tangaroa arrived back in Wellington Port on Monday with 18 scientists from New Zealand, Australia and France after a trip to the Southern ocean to investigate whale activity.

The international scientific team returned with data showing whales can be researched without being killed.

It was the world's largest, non-lethal whale research expedition and it returned with a range of new information that would help future marine mammal conservation, the New Zealand Press Association reported on Monday.

The six-week expedition collected more than 60 biopsy samples, took many photo-identifications of humpback whales and acoustics data.

The scientists also placed 30 satellite tags on humpback whales to provide movement data on the feeding grounds and migration routes back to the tropical breeding areas in winter.

The scientific team said it would analyze the data over the next two months to get a clearer picture on a "range of important conservation science issues such as whale movement and feeding behavior, defining migratory routes, and mixing patterns between different breeding populations."

Research from the voyage would be presented to the International Whaling Commission meeting in June in Morocco.

The expedition was the first major project under the Southern Ocean Research Partnership formed last year. The expedition also set out to disprove Japan's claim whales had to be killed for research.