The last of 30 Greenpeace activists has been granted bail in Russia after months of pre-trial detention over protesting against offshore oil drilling in the Arctic.

Thursday's court decision will see Australian Colin Russell, 59, released from a St Petersburg detention centre after a two-million-rouble ($60,000) bail is posted, Greenpeace said. 

Russell was a crew member on the Arctic Sunrise, a Greenpeace icebreaker forcibly boarded by Russian coast guards after the September 18 protest, in which activists tried to climb an oil platform run by state-controlled Gazprom.

All 30 people arrested were initially charged with piracy, but the charges were reduced to hooliganism and still face up to seven years in prison if convicted.

Russell's 29 fellow protesters have already been freed on bail, but he was denied bail in hearings earlier this month. However, his appeal was successful.

Uncertainty remains

It is uncertain when the non-Russians in the group, which includes people of 18 nationalities, will be able to leave Russia.

"None of us will truly be celebrating until they've been allowed to return home and the charges against them have been dropped," Ben Ayliffe, a Greenpeace Arctic campaigner, said in a statement, adding that they would remain in St Petersburg for now.

The Prirazlomnaya platform is Russia's first offshore oil rig in the Arctic, where production of hard-to-reach hydrocarbon resources could bolster Russia's energy-reliant economy. President Vladimir Putin has called Arctic shipping and development a priority.

Greenpeace has dismissed the charges as unfounded, saying the protest was a peaceful attempt to draw attention to potential environmental damages threatened by drilling in the relatively pristine region.

The arrests have drawn criticism from the West and were seen by Kremlin critics as part of a clampdown on dissent by Putin.

Source: Agencies