The mother of a British video journalist held in Russia as a crew member of Greenpeace's Arctic Sunrise ship appealed Saturday for his release, saying that she hoped "common sense... and justice" would prevail.

"Punishment should fit the crime, and for what happened that day I think they've more than served their punishment," Ann Bryan, the mother of 29-year-old Kieron Bryan, told reporters at a protest outside the Russian embassy in London.

"I just hope that common sense, and a sense of fair play and justice, will come out of this.

"Kieron is not a pirate, he's not a hooligan, he's a hard-working, decent young man and he's a journalist. He was just doing his job."

About 40 of Bryan's supporters on Saturday handed the Russian embassy a petition signed by 1,400 fellow members of the media, including editors of all of Britain's major national newspapers, calling for his release.

They held a silent protest with stickers across their mouths reading "Free Kieron, free speech, journalism is not a crime".

Bryan was one of six Britons on board the Greenpeace ship after he was hired by the environmental campaign group to document a protest against oil exploration in the Barents sea.

The 30 people on the ship, including 26 foreigners from 18 countries, were arrested in September when two activists tried to scale an oil rig.

They were charged with piracy -- which carries a sentence of up to 15 years -- after their ship was boarded by Russian coastguards on September 19, and have been placed in pre-trial detention until November 24.

Bryan's brother, Russell, told the BBC on Saturday: "He's kept in one cell for 23 hours a day.

"It's a very difficult position for him to be in in terms of the darkness and the cold of the cell. It's very difficult. He's alone with his thoughts for a lot of the time."

Russian investigators said Wednesday they had reclassified the crime as hooliganism, a lesser charge, but Greenpeace said Friday that the activists never received documents formally lifting the piracy charge.

It added that the detainees were being moved from their jail in the Arctic Circle city of Murmansk to St Petersburg.

The Netherlands has taken legal action against Russia over the detentions, with a first hearing next Wednesday at the International Tribunal for the Law of the Sea in Hamburg, Germany.