Human rights court criticizes Russian Katyn massacre inquiry MOSCOW, Oct. 21 (UPI) -- A European human rights court criticized the Russian government for failing to declassify documents from its investigation into the Katyn massacre. The European Court of Human Rights said Russian officials should have honored repeated requests by Polish families and officials to release documents related to the 1940 World War II incident where Russian soldiers executed some 22,000 Polish prisoners of war in the Katyn forest in April and May of 1940, RIA Novosti said Monday. The Russian government denied it was responsible for the slaughter for 50 years, instead saying Nazi troops were responsible. It wasn't until 1990 the Russians formally admitted they carried out the killings. A group of families of those who died in the Katyn massacre brought their case to the human rights court, where judges agreed Russia should release documents related to the initial inquiry and its 2004 decision to formally terminate the investigation. Russia has maintained the documents are irrelevant because those responsible for the killings are all dead. The issue has strained relations between Poland and Russia for years. The human rights court did not comment on the quality of the initial investigations into the Katyn massacre because a panel of judges said they had no standing because those investigations began in the 1940s and the court wasn't established until 1950.