Anthony Perrett has become the first of five British Greenpeace activists to be released on bail after spending two months in detention.
Mr Perrett, from Newport in South Wales, joined four other Britons who are part of the so-called Arctic 30 to leave a detention centre in St Petersburg after being arrested during a protest against Arctic oil drilling.
Greenpeace confirmed to The Independent that he was joined by British journalist Kieron Bryan, who was also freed today and Alex Harris, Frank Hewetson, and Iain Rogers.
Philip Ball has been granted bail today, but has not yet been released.
Petere Wilcox, the US captain of the ship and six crew members also walked out of prison today.
Three Russian nationals were released on Monday.
Greenpeace said all six have been moved to an undisclosed location in the city with other campaigners.
Ms Harris revealed she was kept in a cell on her own after being taken to a prison in Murmansk.
“For the first week it was really harsh. It was nerve-wracking,” she told BBC News immediately after being released.
“I was in a cell on my own. You do get used to it, but it was tough.”
The move followed the sudden decision by the Russian court to stop refusing bail this week, although it is unclear if they will be allowed to leave Russia.
After watching the live pictures of Mr Bryan walking out of jail, his father Andy Bryan said: "We're absolutely thrilled Kieron is out. He looks tremendously relieved, in good shape, and doesn't seem to have lost his sense of humour either.
"Now we just can't wait to speak to him and then we'll hopefully be able to see him in person too. Of course there are still these terrible charges hanging over him. He feels a terrible injustice has been done but has also made it clear that he intends to clear his name."
The so-called Arctic 30 - 28 Greenpeace activists and two journalists - are awaiting trial on hooliganism charges, which carry a maximum sentence of seven years, after being detained aboard the Arctic Sunrise ship during the protest on 18 September. They were initially charged with piracy, which carries a more severe sentence of 15 years imprisonment.
Greenpeace said it was drawing attention to Shell and its Russian partner Gazprom's planned joint venture to drill for oil in the Arctic.
However, bail was refused for Australian crew member Colin Russell, who was the first to be heard on Monday. A Greenpeace lawyer said an appeal would soon be filed seeking to secure his release as well, according to the RIA Novosti news agency.
Bail has been set at two million roubles (£38,000) for each detainee.
A UN maritime tribunal in Hamburg, Germany, ordered Russia yesterday to free Greenpeace’s Arctic Sunrise ship.