Anti-whaling activist Paul Watson arrested for ramming boat 10 years ago

Paul Watson, the founder of Sea Shepherd Conservation Society, was detained at Frankfurt airport on Sunday on an international warrant filed by Costa Rican authorities accusing him of a "violation of ships traffic" during an incident which occurred 10 years ago, while filming a documentary called Sharkwater.

He is accused of using his ship, the Farley Mowat, to ram a vessel called the Varadero, which was observed conducting illegal shark-finning activities. In claims filed with prosecutors in 2002, several members of the crew described Watson's behaviour as attempted murder.

Charges against Mr Watson were examined by Costa Rican authorities and swiftly dropped, after videotape of the incident was aired. However the case was recently re-opened by new prosecutors who filed the extradition request under which he is now being held.

In a statement, Sea Shepherd said it understood that Mr Watson is in Frankfurt airport jail and will appear in court today.

"He has been given periodic access to his mobile phone and is being treated well. A fisherman accused Paul of trying to kill him, although it is evident that Paul did not and that evidence is on film."

Best known for the Animal Planet series Whale Wars, Watson founder Sea Shepherd in the late 1970s after falling out with Greenpeace, where he had cut his teeth as an anti-whaling activist.

His high-profile supporters include Martin Sheen, Darryl Hannah, Pierce Brosnan and Christian Bale.

He has been arrested on several occasions over the years, and served 10 days in prison in the 1980s for assaulting a policeman while attempting to disrupt a Canadian seal hunt.

These days, he is famed for the highly-aggressive manner in which he attempts to disrupt the activities of mostly-Japanese whaling fleets.

Opponents have called Mr Watson's leadership style egotistical and overbearing, and say that some of his tactics verge on terrorism.

Meanwhile, last year he was the subject of a South Park spoof called Whale Whores.