The Katyn forest massacre of around 22,000 Polish officers and other prisoners by the Soviets were kept under wraps by US government officials, according to documents released Monday, the Associated Press reported.
American troops who found the bodies in a state of decay in the Russian forest in 1943 sent coded messages back home about what they saw. Though the evidence could have changed the course of the Soviet treatment of Poland, it was instead buried by American officials at the highest levels of government, the Associated Press reported in an exclusive.
The "long-held suspicion," according to the AP, is that Roosevelt was attempting to hang on to his alliance with Josef Stalin and Russia, to whom the Americans were looking to help them win World War II against Germany.
The secret codes sent by two American POWs, which suggests Roosevelt's administration knew about the massacre, is just some of the evidence found in the 1,000 pages of declassified documents being released online by the United States National Archives.
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The Katyn massacre caused international discord when the Nazis exhumed the Polish victims in 1943 and blamed the Soviets for their murders, according to the Katyn Forest Massacre association's website. In 1944, when they retook the Katyn forest region, the Soviets exhumed the Polish bodies once more and pointed fingers at the Nazis.
It was not until the Soviet Union collapsed that Russian Premier Gorbachev admitted in 1989 that the NKVD had killed the Poles.
In April 2010, Russia released their documentation of the Katyn massacre online, at the behest of Russia's president Dmitry Medvedev, the Guardian reported.
A special US Congressional committee set up to investigate the atrocities called the massacre "one of the most barbarous international crimes in world history" in their 1952 report, according to the UK Press Association.