Russian troops 'died in Ukraine'
Russian opposition activists have published a report they claim proves Moscow is deeply involved in the war in Ukraine, seeking to counter state media reports casting the events as a local uprising against the Kiev government.
Prominent Kremlin critic Boris Nemtsov was working on the report - entitled "Putin.War" - at the time of his murder in February.
Drawing on media accounts, evidence from relatives and other representatives of dead soldiers and confidential sources, the 64-page report maintains that hundreds of Russian troops have died fighting in a war that has cost Russia hundreds of millions of pounds.
Opposition activist Ilya Yashin, who presented "Putin.War" in Moscow, said that by conservative estimates at least 220 Russian soldiers had died in two battles in eastern Ukraine in the past year.
Mr Yashin said the real number might be much greater but that he would give figures only for deaths that could be confirmed.
The Russian Defence Ministry has denied any of its soldiers have fought in Ukraine, saying that the Russians who have joined the armed separatists were volunteers.
The report claimed the soldiers were released from their duties in the army and listed as volunteers. The Defence Ministry promised to pay compensation if the soldiers were killed or wounded, but failed to live up to its commitments, the report said.
Mr Yashin said Russian government actions have harmed the country's standing in the world and economic well-being.
"The policies pursued by (president Vladimir) Putin, the isolationism into which he has forced our country, this war he has waged against our brother nation, all of it goes against the interests of Russia," he said.
Mr Nemtsov was shot dead on February 27 in central Moscow. Five suspects, including a Chechen police officer, were arrested, but investigators have not named a suspected mastermind and the motive remains unclear.
Mr Yashin said Mr Nemtsov might have been murdered because of his investigation.
"That is one of the theories of what may have been behind his killing," he said.
He added that researchers on the report had been subject to intimidation but they would not be deterred.
"They killed Nemtsov, so we took over. If they don't let us work, others will take our place," he said.
According to Mr Nemtsov's sources, at least 150 Russian soldiers died in August. Their relatives received two million rubles (now worth about £25,000) in compensation and signed non-disclosure documents.
Around 70 more Russian soldiers died in January and February in fighting around the city of Debaltseve, the report said, adding that family members were unable to receive compensation and appealed to Mr Nemtsov for help.
Many Russian citizens engaged in fighting in eastern Ukraine have freely admitted where they come from, but stopped short of confirming they are fighting under Moscow's orders.