The Investigative Committee, which is in charge of the high-profile probe against the 30 arrested on the ship that was protesting Russia's offshore oil drilling in the Arctic, initially accused the activists of piracy.
However, last Wednesday the Committee, Russia's equivalent of the US FBI, said in a statement that it had reclassified the crime as hooliganism, which carries a lesser sentence.
"The investigation has requalified the charges," the Committee said in a statement on 23 October. The new charge could still be punishable by up to seven years in prison.
Greenpeace, however, said on Friday that investigators have not presented the jailed activists or their lawyers with any official papers that cancel the previous charge, as would be required to actually remove it formally.
The organisation's executive director Kumi Naidoo said in a statement that instead of lesser charges, the activists now face potentially even longer jail terms.
"First this saga shocked people across the world, now it has descended into farce," he said in a statement, adding that the activists are "neither pirates nor hooligans".
Activists, journalists jailed
Through the week, activists and journalists who were on the ship and are now jailed in pre-trial cells in northern Russia's Murmansk, received their hooliganism charges, according to the organisation.
Greenpeace spokesperson Maria Favorskaya told AFP that "essentially, right now all 30 people have two charges".
The allegations came as French Prime Minister Jean-Marc Ayrault met with Russian counterpart Dmitry Medvedev and President Vladimir Putin in Moscow, raising the issue of a French national who is one of those held.
"I asked that he would make a humanitarian gesture toward [French activist Francesco Pisanu]," Ayrault told journalists after meeting with Medvedev.
The Russian prime minister said that Russia will not condone anyone's attempts to "influence technically complicated and unsafe processes" associated with extraction of natural resources, because objects like platforms are essentially "like a powder keg".
Favorskaya said that the hooliganism charge does not even work in international waters, where Greenpeace says the ship was boarded by coast guard on 19 September, after several activists scaled the Barents Sea rig belonging to state energy giant Gazprom.
The Investigative Committee has, however, made no new announcements since last week, with a representative telling AFP on Friday that "there is no new information".