A court in the Netherlands has ordered Russia to pay compensation for seizing the Greenpeace ship Arctic Sunrise during a protest against an offshore oil platform two years ago, a ruling which Moscow dismissed as lacking legal authority.

The Permanent Court of Arbitration, which resolves disputes between states, said the decision was taken unanimously.

It found that by arresting and seizing the Arctic Sunrise and its crew of 30, without the consent of the Netherlands, Russia had breached its legal obligations.

The case has added to already strained diplomatic relations between Russia and the Netherlands, which came to a head over last year's downing of Malaysia Airlines flight MH17 over eastern Ukraine which had many Dutch tourists on board.

In the Arctic Sunrise case, the Netherlands is entitled to compensation with interest for costs and damages, the court found. The amount will be set at another hearing.