Tokyo would be strongly condemned if Paul Watson, founder of antiwhaling group Sea Shepherd, is extradited to Japan and found guilty, Robert Read, an executive of the Captain Paul Watson Foundation, said in a recent interview.

"If Japan ever gets Paul into trial in Japan, it is actually going to be counterproductive for Japan because they are going to put whaling on trial by doing it in the global attention," said Read, COO of the sea protection group formerly known as Sea Shepherd U.K.

His possible trial in Japan would create "a martyr situation for whaling," he said. "Japan will actually get greater global attention on its whaling, not less."

Read asked Japan if it "really wants to be known for imprisoning one of the world's most famous whale conservationists and him dying in a Japanese jail," adding, "I think that it is a big mistake by Japan, because the global attention will actually increase on Japanese whaling."

Watson was placed on an international wanted list in 2010 on suspicion of obstructing Japan's research whaling. Last month, he was detained in Greenland, an autonomous territory of Denmark. Japan is seeking his extradition.

Calling for Watson's release, Read argued, "We don't believe you get a fair trial (in Japan)."

Watson may be sentenced to 15 years in jail, which would be "a life sentence for him," Read claimed. Such a sentence is "outrageously excessive" for an environmental campaigner, he said.

Meanwhile, the process of deciding whether to extradite Watson could be prolonged, Read suggested.