(AP) -- An anti-whaling group banned one of its members for carrying a weapon onboard ship as a strategy to help him avoid prison in Japan, and he's free to rejoin its protests, the group's leader said Thursday.
A Tokyo court on Wednesday convicted New Zealander Pete Bethune of assault and obstructing Japanese whaling ships in the Antarctic Ocean earlier this year, but suspended the two-year prison sentence.
Bethune, 45, climbed onto the whaling ship Shonan Maru 2 in February from a Jet Ski to confront its captain over a collision the previous month that sank the Sea Shepherd protest vessel Bethune skippered.
During the trial, Sea Shepherd announced it would not let Bethune join further protests because it found he had loaded a bow and arrows onto his vessel before it set sail - even though he didn't intend using them against the Japanese whaling ships.
Sea Shepherd founder Paul Watson said Thursday that ban "was really just a legal strategy" as "the Japanese judges would (have been) hesitant to release Pete ... if they knew he was going to be (back) down in the southern ocean."
"We spent half a million dollars and put every bit of thought we could into getting him out of prison and that was a strategy," he told New Zealand's National Radio.
"He's a hero to the conservation movement and we'd certainly welcome him back," he said. Bethune said earlier he was not planning to take part in anti-whaling protests in the coming Antarctic summer season.
Sea Shepherd has been protesting Japan's whaling in Antarctic waters for years, and often has engaged in scuffles with Japanese whalers. It claims the research whaling program, an allowed exception to an international whaling ban, is a cover for commercial hunting.
Glenn Inwood, New Zealand spokesman for Japan's Tokyo-based Institute of Cetacean Research, said Bethune's conviction showed "Sea Shepherd is a criminal organization."
Watson vowed that the group would return to Antarctica this season to continue its campaign against the Japanese whalers. Inwood said the whalers also planned to return.
New Zealand Prime Minister John Key called on both sides to keep "cool heads" while the international community struggles to come up with a compromise acceptable to whaling and non-whaling nations.
Explore further: The green lungs of our planet are changing