A marine conservation group has been ordered to pay £520,000 in security fine to get its ship released from Lerwick harbour in Shetland.

The ship was seized more than a fortnight ago after a judge at the Court of Session in Edinburgh ordered its seizure following an action for damages raised by a Malta based Fish and Fish. The action from the firm comes in a dispute over the group’s direct action against its bluefin tuna fishery last year.

Sea Shepherd was expected to begin voyage from Shetland on Wednesday morning after it paid £520,000 into court to secure its release. The sum is less than originally sought by the firm. Fish and Fish is suing Sea Shepherd for £736,000 in damages and had sought £660,000 in security for the vessel.

There were concerns that the group will now have to sell the ship to raise the money for the fine. The Steve Irwin ship was involved in demonstrations against the Faroe Islands' annual pilot whale cull. Activists are hoping to resume the action by joining its sister ship, the Brigitte Bardot, in Faroese waters this week.

Paul Watson, the group's founder expressed optimism that the group wll be able to get the ship released. "The bond has been paid, so the ship will seek port clearance in the morning and sail for the Faroe Islands," he said.