Moscow will allow the foreign crew members of Greenpeace ship Arctic Sunrise to leave Russia as soon as they obtain legal status to do so, a high-ranking Kremlin official said Saturday.

"As soon as the issue of how they can leave Russian territory is regulated, I think they will leave," said the Kremlin Chief of Staff Sergei Ivanov, RIA-Novosti agency reported.

"Nobody will hold them," he said.

Interfax news agency reported that the issue hindering the crew members' departure is their lack of Russian visas.

A Greenpeace official said however that local migration officials were not granting transit visas until all charges were lifted against the activists.

A court in Russia's northwestern city Saint-Petersburg this week granted bail to all but one of 30 crew members of the Dutch-flagged ship, which was detained by Russia after several activists attempted to scale a Barents Sea oil rig belonging to Russian company Gazprom in a protest against offshore drilling.

Australian Colin Russel, the ship's radio operator whose case was the first to be heard in a series of court proceedings this week, was denied bail and for now remains in the Saint Petersburg jail.

One of the people to go before the judge Friday, British national Philip Ball, was granted bail but has not walked out of the jail yet due to a technicality, said Greenpeace lawyer Mikhail Kreindlin.

"They don't have visas, they were registered by migration officials in a hotel, but they are free to move around," Kreindlin told AFP.

"Nobody really understands their status," he said, adding that local migration officers told him they would grant transit visas to the foreigners only after all charges are lifted.

The crew is currently charged with hooliganism. They were initially charged with piracy, a heavier crime, but investigators later dropped the piracy charge.

The ship Arctic Sunrise is still detained at port in Russian northern city Murmansk, although a Friday ruling by the International Tribunal for the Law of the Sea, ordered that the vessel and the crew be "released and allowed to leave" Russia upon the posting of a 3.6 million euro bond.

Ivanov said Russia will not react to the ruling.

"The issue will be solved... according to Russian laws, not somebody's political wishes," he said.