Not so long ago, the people behind the Oscar-winning documentary "The Cove" were thrilled that a domestic release of their work would appear in Japan, site of the deadly dolphin slaughter chronicled in the film.

Unfortunately, it appears that efforts by a right-wing nationalist group to block the film from being shown are proving effective. Variety is reporting that three more theaters in the northern cities of Sendai, Yamagata and Aomori have decided against showing the documentary. That brings the total to five that have backed out.

In addition, Tokyo's Meiji University has canceled an on-campus screening of "The Cove" that was to have been followed by a Q&A with the star of the film, dolphin activist Ric O'Barry. The university cited that the screening would have interfered with classes — but the group sponsoring the event doubts the sincerity of that reason.

In a statement, the Contemporary History Research Society said that it wanted "the university to think carefully about the freedom of expression guaranteed in the Constitution."

O'Barry agreed, calling the cancellation an "assault on democracy".

"This is not North Korea. It's not China and it's not Cuba. It's a democratic society. There's a very small minority of radicals who are going to theater owners and threatening them. They don't want people to see this film," he told ABC News.

Despire the protests, film distributor Unplugged has vowed to continue with the scheduled screening, originally slated for 26 theaters.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

'Cove' cancellations grow in Japan
Under pressure from protesters, theater owners back down on showing award-winning film.