The Japanese distributor of a controversial documentary about the slaughter of dolphins will begin screening it in Tokyo despite a series of protests by ultra-nationalists.

The Cove is an Oscar-winning documentary about the annual slaughter of dolphins in the Japanese village of Taiji.

It has drawn the ire of rowdy ultra-nationalist protesters who have been picketing the Tokyo office of the distributor, accusing the company of Japan-bashing.

Despite the demonstrations, the distributor says the film will now be shown in six movie theatres from next month in the first commercial screenings in Japan.

Some cinemas have buckled to pressure from the protesters and agreed not to show the documentary.