Whaling and eating whale meat have been heavily criticised by conservation groups, but officials in Japan argue that it is part of the country’s culture and way of life.

The Danish justice ministry confirmed that it would not be complying with the Japanese extradition request, basing its decision on “the nature of circumstances” as well as the fact that the incident dated back 14 years.

His lawyer Julie Stage told the AFP news agency that he was now free.

As Greenland is an autonomous territory of Denmark, the decision on his extradition was made in Copenhagen. Although Japan and Denmark have no extradition treaty, the government in Tokyo had asked Denmark to hand him over.

Denmark’s justice minister, Peter Hummelgaard, said it had been of “central importance” to ensure that the length of time Mr Watson had been detained in Greenland would be deducted from any possible prison sentence he may have later faced in Japan.

He added that the ministry concluded “it cannot be assumed with the necessary certainty that this will be the case” after correspondence with Japanese authorities.