( CNN ) -- Kremlin critic and former oil tycoon Mikhail Khodorkovsky , released from more than 10 years of imprisonment in Russia last week , praised the two freed Pussy Riot rockers for enduring months of hell in prison . `` Dear girls . I know that the last months have been a living hell for you , and I am happy to learn that this torture , unworthy of a European country in the 21st century , has ended . `` Releasing political prisoners makes those in power at least a little more humane What is probably most important for you now , is to find the strength not to keep any hatred and anger in your hearts , after your ordeals of imprisonment . Congratulations ! '' The punk rockers were thrilled by his comments . `` It 's amazing . It would be so great for us to work with him , '' Nadezhda Tolokonnikova said . With the Sochi Olympics less than two months away , Russia has freed high-profile prisoners in recent weeks . A new amnesty law introduced by President Vladimir Putin allowed two members of Pussy Riot to leave prison on Monday , two months before the end of their two-year sentences for a performance critical of Putin . According to Russian media , Tolokonnikova and Maria Alyokhina qualified for amnesty under the new law because they have young children . And last week , Putin pardoned Khodorkovsky , who had been jailed since 2003 and was convicted in 2005 of tax evasion and fraud . Russia 's international image has suffered from an anti-gay law passed under Putin , and there have been threats of protests and boycotts at the Olympics over its bans on `` homosexual propaganda . '' The `` Arctic 30 '' Russia has dropped its case against at least one of the Greenpeace `` Arctic 30 , '' the environmental group said Tuesday on its Arctic Sunrise Twitter feed . According to Greenpeace , crew members of the Greenpeace ship Arctic Sunrise were peacefully protesting at an oil rig to bring attention to the threat of oil drilling and climate change . The oil rig belonged to Gazprom , a Moscow-based company . The Arctic 30 includes 28 Greenpeace activists and two freelance journalists . They were detained in September after two activists left their ship and tried to scale the oil platform . Russian authorities have accused the activists of trying to take over the oil platform and of endangering the lives of the company 's employees . They say the activists ' actions could have led to an environmental disaster . Most of the activists were released from jail by late November , but still faced charges of hooliganism . Russian authorities release most of Greenpeace protest group . Greenpeace spokesman Aaron Gray-Block said the Arctic 30 will be free to leave Russia once they get the proper stamps in their passports from the migration service . `` We know that getting those stamps would be the best Christmas present for the Arctic 30 , and we hope it can occur quickly , '' Gray-Block said . CNN 's Tom Cohen , Diana Magnay and Phillip Taylor contributed to this report .
NEW : Punk rockers say they hope to work with former oil tycoon on reform . Pussy Riot says Khodorkovsky rockers went through `` living hell '' The `` Arctic 30 '' includes 28 Greenpeace activists and 28 freelance journalists . The group was detained after some tried to scale a European company 's oil platform .