Wellington, Feb 13 NZPA - Whaling protesters aboard the Sea Shepherd have refuted allegations from their Japanese adversaries that they were injured when hit by flying acid during a southern ocean clash, with the protesters claiming the crew members pepper-prayed themselves by mistake.

The Japanese Institute of Cetacean Research (ICR) yesterday said three crew members in the Atlantic Ocean with the whaling fleet suffered face and eye injuries from acid fired by the protesters.

Japanese Fisheries Minister Hirotaka Akamatsu was furious when he heard of the allegations. "I am full of rage. I could not believe they did such a thing," he said.

The Sea Shepherd protesters said they shot butyric acid, produced from stinking rancid butter, which they often aim at the whalers to try to disrupt the annual Japanese hunt, but maintain butyric acid is nontoxic.

"The Sea Shepherd Conservation Society has video footage as proof that the media release by the ICR was a lie and an attempt to accuse Sea Shepherd of injuring Japanese crew members," the society said today.

The Sea Shepherd said the Japanese crew members had tried to fire pepper spray at protesters on an inflatable boat, but the wind had caused the spray to blow back in their faces.

A video released by the society shows two Japanese crew with tanks on their backs spraying something toward the protest boat.

Sea Shepherd captain Paul Watson said the society had never caused an injury to anyone since it was founded in 1977.

"I think this video absolves Sea Shepherd of any wrong-doing and demonstrates that the Japanese whalers routinely spin their stories to demonise our efforts to defend the whales from their illegal activities," he said.

Clashes between the two groups have been ongoing, but came to a head last month when one of the Japanese boats collided with protest boat the Ady Gill, the later sinking after suffering significant damage.