Russia's state-held energy giant Gazprom said Friday it had launched production at an Arctic oil rig raided in September by 30 Greenpeace activists whom the authorities later detained for two months.
The landmark announcement marked the formal start of Russia's long-planned effort to turn the vast oil and natural gas riches believed to be buried in the frozen waters into profits for its ambitious state energy firms.
But it is also certain to outrage campaigners who see the Arctic as one of the world's last pristine reserves whose damage by oil spills and other disasters would be enormously difficult to contain.
Gazprom made its announcement in a statement that stressed that the company also had rights to 29 other fields it planned to exploit in Russia's section of the Arctic seabed.
"Gazprom has begun oil production at the Prirazlomnoye deposit," the company said in a statement.
"This is the first project in Russia's history aimed at developing the resources of the Arctic shelf and the start of large-scale work by Gazprom that will create a major hydrocarbons production centre in the region."
Several Greenpeace activists aboard the Arctic Sunrise icebreaker attempted to board the Prirazlomnaya platform on September 18.
Russian coastguards helped the Gazprom crew fend off the open-sea protest.
Armed security agents later boarded the Arctic Sunrise and arrested the crew of 28 activists and two journalists.
The group hailed from 18 countries besides Russia and saw governments ranging from Australia to Britain criticise the arrests.
The crew was initially accused of piracy before those charges were reduced to the lesser crime of hooliganism.
Russia's parliament approved a Kremlin-backed amnesty this week that should end the prosecution of the entire crew.
Explore further: Oil globs close Los Angeles-area beaches to swimming (Update)