The arrest of Sea Shepherd founder Paul Watson in Frankfurt on Sunday is unlikely to lead to his arrest by Japan for a combination of reasons, one being that Tokyo does not have an extradition treaty with Berlin, according to Toru Chochi, a Japan Coast Guard official.

Also, the type of notice Interpol issued does not guarantee Watson's extradition but only means that member countries, including Japan, are to share information on him, Chochi said.

German police arrested Watson and he is likely to be extradited to Costa Rica at a later date. Costa Rican police accuse him of obstruction of shark-finning operations as well as attempted murder during a confrontation with shark fishermen in 2002.