The crew's other 14 members were similarly charged on Wednesday. In addition to Russia, the activists come from 17 other countries.

The charge, which carries a 15-year prison term, was filed on Thursday against 16 members of the crew, including a prominent Russian freelance photographer.

Russian investigators have charged the entire 30-member crew of a Greenpeace ship with piracy for a protest at an oil platform in the Arctic.

The Russian Coast Guard seized the environmental group's Dutch-flagged Arctic Sunrise and all on board, after the September 18 protest at the offshore platform owned by Russian state-controlled energy giant Gazprom.

The nationalities represented Those arrested are from: Argentina, Australia, Brazil, Canada, the Czech Republic, Denmark, the United Kingdom, Finland, France, Italy, the Netherlands, New Zealand, Poland, Russia, Sweden, Turkey, Ukraine and the United States.

"All 30 participants in the criminal case have been charged over the attack on the Prirazlomnaya platform," the Investigative Committee said in a statement.

"They are all charged with piracy by an organised group."

The activists are now in custody in the city of Murmansk.

Those charged Thursday also included the ship's captain, American Peter Willcox, who was the captain of Greenpeace's Rainbow Warrior ship, bombed by French agents in New Zealand in 1985.

Greenpeace denies any wrongdoing and describes the Russian charges as absurd.

"Our activists have been charged with a crime that did not happen," Kumi Naidoo, the group's international executive director, said.

"A profound injustice is right now being perpetrated against our friends, our brothers and sisters, our sons and daughters who sit in Russian jails."

Several activists scaled the oil platform in the Barents Sea to denounce Russia's plans to drill in the pristine Arctic.

Russian border guards then lowered themselves onto the Arctic Sunrise from a helicopter, locked up the crew and towed the ship to Murmansk.