Greenpeace has started to lodge applications seeking exit visas for the group of 30 activists and freelance journalists arrested during a protest against oil drilling in the Arctic.
The group said the 26 non-Russian nationals, including six Britons, three of whom are from Devon, have had their passports returned to them after being freed on bail by courts in St Petersburg, but do not have visas to leave Russia.
The 28 activists and two freelance journalists were initially charged with piracy after being arrested in mid-September, but the charge has since been changed to hooliganism.
Jasper Teulings, general counsel at Greenpeace International, said: "This is a unique situation where the Arctic 30 were charged and then bailed inside Russia after they were detained in international waters beyond Russia's territorial waters.
Ben Ayliffe, Arctic campaigner at Greenpeace International, added: "Greenpeace cannot be certain whether the exit visas will be granted and we cannot promise when our friends will be able to leave Russia, but we are doing our best to get them home as soon as possible."