New Zealand has rejected calls from marine biologists to improve the protection of the rare Maui or "hobbit" dolphins.

According to the International Whaling Commission's (IWC) Scientific Committee, the Maui dolphins will soon become extinct unless the government will ban fishing in their habitat.

Scientists said there are about 50 Maui dolphins left in North Island's shallow waters. Based on estimates, about three to four dolphins are killed by accident via fishing annually.

Nick Smith, New Zealand's conservation minister, did not agree with the death toll saying a ban covering 6,200 square kilometers was already successful in reducing the number of Maui dolphin deaths.

The IWC may be calling for a total fishing ban in the area and an extension of 20 nautical miles from the coast. Smith said no proof has been presented to support the claim that dolphins are found outside the protected area.

In an interview with Radio New Zealand, Smith cited the IWC is asking the government to "shut down" the whole fishing industry in North Island's West Coast and in areas where there's no evidence of Maui dolphins.

The Maui dolphin is the smallest and rarest dolphin in the world. Named after a Polynesian demigod, the dolphin has a maximum length of up to 1.7 meters.

Reports said the New Zealand government was accused of being "hypocritical" for denouncing Japan's scientific whaling program while it continues to ignore the recommendations of the IWC. Smith has denied the claims.

The United Nations has issued a court order to ban Japan from whaling earlier this year. New Zealand and Australia had filed an appeal to stop the Japanese program.

Smith said there is a "big" difference between the UN International Court of Justice and the technical committee of the International Whaling Commission.

But conservation group NABU International said the IWC is only one of the scientific bodies that are calling for more protection for the Maui dolphins. The Society for Marine Mammalogy and the International Union for Conservation of Nature also agree with efforts to further protect the animal.

NABU Endangered Species Specialist Barbara Maas said Smith has a "fantastical stance" that everyone else is wrong about the need for further protection.

She stressed it's time for the government to stop "playing politics" and face the facts to save New Zealand's 50 Maui dolphins.