SEA Shepherd crew members and supporters gathered in front of the German consulate in Battery Point yesterday, protesting for the release of Captain Paul Watson.
Capt Watson was recently arrested in Germany on an outstanding warrant for charges relating to an incident in Guatemalan waters in 2002.
He may be extradited to Costa Rica to face charges related to a violation of ships traffic incident involving a Costa Rican vessel, the Varadero, illegally hunting for shark fins.
"The crew of the Varadero accused the Sea Shepherd leader of trying to kill them, while the video evidence proves this to be a fallacy,"a Sea Shepherd spokesman said.
They said Capt Watson and his ship intercepted the Varadero on the orders of the Guatemalan Government but later encountered a Costa Rican gun boat, the crew of which has accused Capt Watson of attempted murder.
Speaking yesterday in front of the German consulate, Sea Shepherd crew member Ben Potts, from Sandy Bay, said he was concerned for Capt Watson's safety.
"Should he be extradited to Costa Rica, he will certainly not receive a fair trial and his safety cannot be guaranteed," he said.