Anti-whaling activist Paul Watson could face up to 15 years in prison in Japan, after the founder of US-based group Sea Shepherd was arrested on an international warrant in Greenland earlier this month. According to the Japan Coast Guard, Watson, who is also a co-founder of Greenpeace, is facing charges including accomplice to assault and ship trespass, after he was arrested on an international warrant in Greenland. The charges stem from the anti-whaling group Sea Shepherd Conservation Society’s alleged boarding of the Japanese whaling ship Shonan Maru 2 in the Southern Ocean in February 2010. The statutory penalty for such crimes ranges from up to three years in prison or a fine of up to 100,000 yen (£503.10) for vessel trespassing to up to 15 years in prison or a fine of up to 500,000 yen (£2,515.50) for assault, according to Japan’s Ministry of Justice. A spokesperson for the ministry stressed these punishments are general information and do not refer to any specific case, adding they may apply to both principals and accomplices. The head of the French branch of Sea Shepherd, Lamya Essemlali, visited Watson in custody in Nuuk, Greenland, on Monday and said in a statement that Watson was “doing well” and had “no regrets”. Activist Peter Bethune, then a member of Sea Shepherd, allegedly boarded the Shonan Maru from a jetski in a bid to detain its captain after the group’s speedboat was destroyed in a collision with the Shonan Maru. Bethune was seized by the whalers and eventually arrested in Tokyo on charges of illegal boarding. He was given a two-year sentence, suspended for five years. A warrant to arrest Watson as an accomplice of Bethune was issued in 2010 and an Interpol warrant was filed in 2012 and remained active, a spokesperson for the Japan Coast Guard said. He declined to give his name, citing Coast Guard policy. The boarding of the Shonan Maru 2 followed clashes between the protesters and whalers that forced Japan’s whaling fleet to return home with barely half its planned catch of whales. Despite a 1986 International Whaling Commission (IWC) moratorium on commercial whaling, Japan was allowed to kill nearly 1,000 whales each year for what it called scientific research. It withdrew from the IWC and resumed commercial whaling in 2019, and launched a new whaling mothership, the 9,300-ton, $47m Kangei Maru, in May on a months-long hunt. The ship’s owner, Kyodo Senpaku, has denied speculation that it will sail to the Southern Ocean for whaling, saying it will target whales around Japan. Known for confrontational whaling protests, the Canadian-American Watson was arrested in Nuuk en route to intercept the Kangei Maru in the north west Pacific, according to the Captain Paul Watson Foundation. The foundation said the Interpol red notice had disappeared months ago. The Japan Coast Guard said that was not the case. Watson will be held in Nuuk until 15 August while Denmark considers his potential extradition to Japan, according to the foundation. He was denied bail on the grounds of being a flight risk. French President Emmanuel Macron’s office has asked Danish authorities not to extradite Watson, who has lived in France for the past year, according to Agence France-Presse. A French online petition urging Macron to demand Watson’s release has garnered almost 670,000 signatures in eight days. Sea Shepherd France said on Tuesday that it had launched a separate online petition addressed to Danish prime minister, Mette Frederiksen, urging her not to extradite Watson.