The Japanese whaling fleet in the Southern Ocean says Sea Shepherd's protest ship is deliberately avoiding its attempts to hand over two detained activists.
Japan's Institute for Cetacean Research claims the Sea Shepherd Conservation Society vessel the Steve Irwin is trying to prolong the controversy.
The Japanese government has agreed to release the Sea Shepherd activists held on the Yashin Maru No 2 since they boarded the catcher boat in the Southern Ocean last night (AEDT).
Institute spokesman Glenn Inwood said phone calls and emails to the Steve Irwin to arrange the handover since the diplomatic agreement was reached have been unsuccessful.
“I believe that they want to continue this for as long as possible,” Mr Inwood told Sky News, referring to the media coverage of the incident.
The spokesman also denied the two men – Australian Benjamin Potts and Briton Giles Lane – had been mistreated on the Yashin Maru, saying they had been given hot meals, a bath and had a good night's sleep.
“They were restrained for a short period (on deck) before being taken to an office,” Mr Inwood said.
“It was the only way, you couldn't have them running around the deck not knowing what they're going to do.
“They're highly unpredictable people and it was that they were restrained for a short period.
The Steve Irwin's captain Paul Watson said the Japanese crew roughed up the activists, tried to throw Mr Potts overboard and tied the pair to a mast in freezing conditions for a couple of hours.
Mr Inwood said the Japanese had displayed tolerance in the face of illegal activity by the Steve Irwin, whose activists had a right to protest but not police the whaling.
“Because Japan's research is legal obviously they're the ones who've broken the law.
“They are just a group of vigilantes seeking publicity and out to cause as much damage as they can.”
He said the Japanese would be considering follow-up legal action against the activists.