Russia is in the process of dropping charges against the remaining 29 Greenpeace crew members who were detained in the Russian Arctic.
Around 20 have been processed, with more expected later as part of an amnesty passed by Russia's parliament.
Twenty-eight activists and two freelance journalists were arrested in September as they staged a protest at a Russian offshore oil rig.
The case against one of the group, Anthony Perrett, was closed on Tuesday.
All 30, of whom six were Britons, had faced charges of hooliganism and were held in jail, first in the city of Murmansk then later in St Petersburg, before being released on bail in November.
The activists had been asked to attend a meeting at Russia's powerful Investigative Committee, where the criminal case against them was being dropped en masse, Greenpeace said.
