LONDON (AP) -- Anti-whaling activist Paul Watson was freed from prison in Greenland on Tuesday and will not be extradited to Japan, the Danish Justice Ministry and defense lawyers said.

Japan had asked Denmark to extradite Watson, who had been in custody in Greenland since his arrest earlier this year under a Japanese warrant. There was no immediate comment from the Japanese Embassy in Copenhagen.

Watson's foundation said he faced a maximum sentence of 15 years in prison in Japan, which does not have an extradition treaty with Denmark.

"After five months it's good to be out and ... good to see that they are not going to send me to Japan, and so have a go-home for Christmas," Watson said in a video posted by his foundation on social media after his release.

"The only hard part was that my two little boys ... I haven't seen them since June," he added.

Watson, a Canadian-American citizen, is a former head of the Sea Shepherd Conservation Society, whose high seas confrontations with whaling vessels have drawn support from celebrities and featured in the reality television series "Whale Wars."

Japan's coast guard sought his arrest over an encounter with a Japanese whaling research ship in 2010 when he was accused of obstructing the crew's official duties by ordering the captain of his ship to throw explosives at the whaling ship.

Watson was sought through an Interpol red notice, and the captain -- a New Zealand citizen -- was convicted of assault and given a suspended prison term, which allowed him to leave Japan.

Japan's government had asked Denmark to hand over Watson so he could be tried in Japan. Greenland is an autonomous territory of Denmark.

Watson was arrested on July 21 when his ship docked in Nuuk, Greenland's capital.

"We are happy and relieved that Paul Watson is now free," lawyer Jonas Christoffersen said. "I guess he will have some lunch or breakfast as a free man and then will find a way to get back home."

Christoffersen said the decision is final.

The Danish Justice Ministry said in a statement that the conditions for extradition were met, but it had not received adequate guarantees from Japanese authorities that the time Watson had already served in custody would be counted against any sentence he would receive in Japan.

Watson left Sea Shepherd in 2022 to set up his foundation, which alleged at the time of his arrest that the action was politically motivated -- and called for his release.

Watson was detained in Germany in 2012 on a Costa Rican extradition warrant but skipped bail after learning that he was also sought for extradition by Japan, which has accused him of endangering whalers' lives during his operations in the Antarctic Ocean. He has since lived in countries including France and the United States.

Japan's says whale meat is part of its food culture and that it supports sustainable use of whales. Japan withdrew from the International Whaling Commission in 2019 and has since resumed commercial whaling within its exclusive economic zone.