GREENPEACE activist Phil Ball could be prevented from leaving Russia after being released on bail.

Phil Ball, 42, from Chipping Norton, is one of the so-called Arctic 30 - a team detained on September after Russian troops boarded their ship the Arctic Sunrise.

The soldiers came on board after four Greenpeace members tried to board a Russian oil platform to protest about drilling in the Arctic.

Earlier this month the Arctic 30 – who face charges of hooliganism – were granted bail and were most recently living in a hotel in St Petersburg while they await their next court date.

But Russia’s powerful Investigative Committee has written to one of the 30 - Anne Mie Jensen from Denmark - saying they are not free to leave the country.

Lawyers for Greenpeace expect all of the non-Russian defendants to be treated in the same way by the authorities, meaning they would now be forced to stay in St Petersburg for Christmas.

In a statement published by Greenpeace, Arctic Sunrise captain Peter Willcox said: “I am ready to go home to my family. We were seized in international waters and brought to Russia against our will, then charged with a crime we didn’t commit and kept in jail for two months.

“A respected international court says we should be allowed to go home, so do numerous Presidents and Prime Ministers, but we can’t get visas to leave the country, and even if we could there’s no guarantee the Investigative Committee won’t schedule an interview for the day I get home, forcing me to break my bail conditions."