The group has been calling for donations by advertising their radical protest activities and apparently has used some of these funds to procure equipment.

Meanwhile, the Japan Coast Guard on Saturday (March 13) inspected the Shonan Maru No. 2 at Yokohama Port with Peter Bethune, a Sea Shepherd activist who was arrested Friday (March 12) on suspicion of trespassing on a security ship belonging to the research whaling fleet. Bethune went to Yokohama Port at about 9am on a JCG patrol ship and boarded the Shonan Maru No. 2 about an hour later.

According to the agency, which has jurisdiction over research whaling, the Sea Shepherd introduced two new protest ships, the 788-tonne Bob Barker and the 26-tonne high-tech powerboat Ady Gil, against Japan's research whaling, which started in Antarctic waters in November.

With the 1,017-tonne Steve Irwin, the group had three protest ships for much of this season - the first time it has had so many since it started protest activities in December 2005 - until the Ady Gil sank following a clash with a Japanese vessel.

The Sea Shepherd group was established by Canadian-born Paul Watson in 1977. The group uploads videos of its protest activities on its Web site, through which it also seeks donations, saying, "With your help, we have saved countless lives of dolphins, seals, whales, fish and much more!"

Many individuals and companies donate to the group.

"The group has abundant funding and therefore it can introduce new equipment every year," said a source related to the Institute of Cetacean Research that has been conducting research whaling.

Meanwhile, according to the Tokyo Coast Guard Office, when Bethune was told by its official in English about his arrest, he agreed to the arrest without protest and admitted to illegally boarding the Shonan Maru No. 2.

The 44-year-old New Zealander has been detained in a facility at the office and will be transferred to the Tokyo District Public Prosecutors Office on Sunday.

Bethune 'deserves harsh penalty'

Japanese agriculture, forestry and fisheries minister Hirotaka Akamatsu called Friday (March 12) for Bethune to be punished harshly. "He should face a harsh penalty because Japan's lenient handling of such incidents has only encouraged Sea Shepherd's activities," Akamatsu said at a press conference Friday (March 13).

Relevant ministries and agencies had agreed to make an arrest if a Sea Shepherd activist trespassed on a ship.

In 2008, two Sea Shepherd activists were held after they boarded a research whaling ship. However, the government soon handed them over to the Australian government, sparking public criticism here.

With that experience in mind, the government has taken a stern attitude toward the latest incident.

The government has asked Australia, where Sea Shepherd has its base, to crack down on the group's protest activities in the country. The Australian police searched two of the group's ships March 6.

However, when a protest ship conducts activities in international waters, only the country where the ship is registered has regulatory power over it.

"Even if Japan asks the country of registry to crack down on a ship, we can't ask the country to send a ship to Antarctic waters," a foreign ministry official said.

While it is possible to crack down on acts of piracy such as robbery based on the UN Convention of the Law of the Sea and the antipiracy law, the foreign ministry does not regard Sea Shepherd protest activities as acts of piracy.