From http://en.wikipedia.org/wiki/Soviet_war_crimes
Soviet War Crimes - ex Wiki
War crimes perpetrated by the armed forces of Soviet Russia and the Soviet Union from 1919 to 1991 include acts committed by the regular army — the Red Army (later called the Soviet Army) – as well as the NKVD, including the NKVD's Internal Troops. In some cases, these crimes may have been committed on express orders — as part of the early Soviet Government's policy of Red terror. In other instances, they were committed by regular army troops as retribution against military or civilian personnel of countries involved in conflict with (or the invasion of) the USSR, or those involved in national liberation movements.Many of these incidents occurred in Central and Eastern Europe before and during World War II, and involved summary executions and mass murder of prisoners of war and mistreatment of civilians in Soviet occupied territories. Although there are documented cases of such incidents, no International Criminal Court or Soviet or Russian tribunal has ever charged any member of the Soviet armed forces with war crimes.
The Soviet State, warfare and war crimes
The Soviet Union did not recognize Imperial Russia's signing of the Hague Conventions (1899 and 1907) as binding, and refused to recognize them until 1955. This created a situation in which war crimes by Soviet armed forces could be eventually rationalized. Soviet refusal to recognize the Hague Conventions (1899 and 1907) also gave Nazi Germany the rationale for inhuman treatment of captured Soviet military personnel.The Red Army and the pogroms
Although early Soviet leaders treated anti-Semitism with "utter contempt", and strong efforts were made by Soviet authorities to contain anti-Jewish bigotry, some Red Army units perpetrated pogroms during the Russian civil war, and the Soviet-Polish War of 1919-1920, notably at Baranovichi. However, only small number of pogroms are attributed to the Red Army, with the vast majority of pogroms in the period having been committed by anti-Communist and nationalist forces. The pogroms were vigorously condemned by the Red Army high command and guilty units were disarmed, while individual pogromists were court-martialed. Those found guilty were executed.
http://en.wikipedia.org/wiki/Allied_war_crimes_during_World_War_II
The "London Cage", a MI19 prisoner of war facility in the UK during and immediately after WWII, was subject to allegations of torture.[22][edit]