In the Katyn' anniversary thread several of our Russian colleagues mentioned the Polish POW camps for Bolshevist prisoners during the Polish-Bolshevik War of 1920. Some of the Russian contributors to this forum even mentioned that these camps were a place of mass extermination of Russian prisoners.
To be sincere, I never heard of such war crimes or POW camps. For sure there were POW camps for Russians in 1920, otherwise the Polish government would have a really serious trouble with dozens of thousands of Russians taken POW. However, apart from the typhoid and flu epidemics, I never heard of any maltreatment of the prisoners. To the contrary, the only example of crimes against the prisoners of war I know is the case of some 1000 Poles taken POW in the Battle of Warsaw by Gay-Khan's Cavalry Corps and murdered by the retreating Bolsheviks shortly before they entered East Prussia.
So, are there any reliable sources to read on the topic? Or is it just a legend, supported by the Soviet propaganda?