The Japan Coast Guard on Friday arrested a member of U.S.-based antiwhaling group Sea Shepherd Conservation Society for trespassing in connection with his boarding of a whaling fleet vessel in the Antarctic Ocean last month.

New Zealander Peter Bethune, 44, was arrested at 11:16 a.m. Friday by the coast guard on the Shonan Maru No. 2, which entered Tokyo Bay at around 10:45 a.m.

Bethune climbed aboard the Japanese vessel after approaching apparently unseen on a Jet Ski.

Bethune nodded and did not resist arrest as the warrant was read to him in Japanese and translated into English, according to Takeo Murui, head of the Tokyo Coast Guard Office who is in charge of the investigation.

“We will work on the investigation of the series of attacks made by Sea Shepherd as well as question the suspect and members of the Shonan Maru No. 2 for details as soon as possible,” Murui said.

By law, the coast guard must send suspects to prosecutors within 48 hours after an arrest is made.

After the arrest was made, Bethune was transferred to a Japan Coast Guard vessel that took him to the quay adjacent to the Tokyo Coast Guard Office in Koto Ward, and driven there under heavy guard by some 100 police officers and coast guardsmen.

Some officers held blue plastic sheets around Bethune as he walked.

An official from the New Zealand Embassy and Bethune’s lawyer met him before the coast guard proceeded with their questioning, the coast guard said.

The JCG also made an inspection of the Shonan Maru No. 2 after it moved to Yokohama.

It plans to have Bethune attend another inspection Saturday.

The Japan Coast Guard obtained an arrest warrant for Bethune on Thursday.

It is the first time the JCG has been involved in a case of ship trespassing in international waters, according to the agency.

Tatsuro Shinjo, deputy director general of the Third Regional Coast Guard Headquarters, said the coast guard decided to handle the arrest because Bethune does not reside in Japan and coast guard officials are to carry out the investigation.

Shinjo said that the captain of the Shonan Maru No. 2 did not make a citizens arrest of Bethune but held him under “protective custody.” Earlier reports said Bethune ostensibly boarded the whaler to “arrest” its skipper after the ship hit his high-tech vessel the Ady Gil in the port bow, chopping it in two, in January. The boat sank shortly afterward.

Both Shinjo and Murui told the media they were informed that Bethune ate the same meals as the other crew members of the Shonan Maru No. 2 and that there were no incidents on the way to Japan. But they were unclear about how much freedom Bethune was allowed on the vessel.

“I assume that the (Shonan Maru No. 2) captain would have had to keep watch over him to a certain extent,” Shinjo said.

After hearing of the arrest, Foreign Minister Katsuya Okada slammed Sea Shepherd’s repeated obstruction of Japan’s whale hunt.

“I have expressed concern over and over again that Sea Shepherd’s interference with our country’s whale research program has been extremely pernicious,” Okada said. “With the arrest of the New Zealander, I believe that things will go accordingly with the judicial proceedings without any fuss.”

Okada added the government must prepare for future interference that may result from the outcome of discussions at the International Whaling Commission or if Australia makes good on its threat to go to the International Court of Justice to stop Japan’s whale hunts.

“The interference of Sea Shepherd has ended for the time being, but the situation could change depending on the discussions of the IWC or (whether) Australia takes this issue to court,” Okada said. “We must keep these things in mind when preparing for the next interference.”

At Harumi Pier, about 10 people, including members of a conservative civic group, called for preserving the country’s whaling culture and denounced Bethune’s actions. About 70 members of the media were also present.

Displaying images of Sea Shepherd members hampering the Japanese whaling fleet, as well as cans of whale meat, the activists demanded that Bethune be harshly punished.

Paul Watson, the head of Sea Shepherd, told Kyodo News he thought it was “very strange . . . the aggrieved captain is the one who is going to be arrested.”

“Pete Bethune was prepared for this, and he said let’s go back to Japan, let’s throw everything out on the table and clear this up,” he said, speaking from Hobart, Tasmania, where the group’s boats are currently docked.

“We are rallying a lot of support in New Zealand and Australia for Pete. He may be considered a criminal in Japan but he’s a hero in Australia and New Zealand,” Watson added.

When the whale boat struck the high-tech speedboat Ady Gil in January, one protester aboard was injured.

Bethune, the Ady Gil’s skipper, reportedly asked his counterpart on the Shonan Maru No. 2 to pay compensation for his boat’s loss.

Japan halted commercial whaling in 1986 in line with an international moratorium, but has hunted whales since 1987 for what it calls scientific research purposes and permissible under a clause allowing “lethal research.”

Environmentalists have condemned the activity as a cover for commercial whaling.

Information from Kyodo added