Environmental activists who protested at an offshore oil platform in the Russian Arctic last week will be prosecuted, possibly for piracy which is punishable by up to 15 years' jail, Russian investigators said on Tuesday (September 24).

They said the "attack", in which Greenpeace activists tried scaling the Gazprom-owned Prirazlomnaya platform, Russia's first offshore Arctic oil platform, had violated Russian sovereignty.

The Greenpeace protest ended when armed officers boarded the Netherlands-registered icebreaker and arrested the 30 activists onboard, Greenpeace said. The vessel, Arctic Sunrise, was towed to the port of Murmansk.

The activists and crew were escorted off the ship late on Tuesday and taken to a local Investigative Committee office, Greenpeace spokeswoman Marina Favorskaya said.

Greenpeace says its protest - aimed to draw attention to the threat oil drilling poses to the fragile Arctic eco-system - was peaceful, and that Russia's actions violated international law.

Greenpeace said the activists had been denied access to lawyers and that they had not yet been formally charged.

Greenpeace says scientific evidence shows that an oil spill from Prirazlomnaya would affect more than 3,000 miles of Russia's coastline.

Presented by Adam Justice