Over 20,000 Polish officers, police and civilians taken prisoner during the 1939 partitioning of Poland by the Soviet Union and Nazi Germany were massacred in the Katyn forest, as well as in prisons and other locations, by the NKVD, the forerunner of the KGB.
The Khamovniki District Court rejected a request for their exoneration in late October.
Last month the European Court of Human Rights agreed to consider pleas from Yezhi Yanowitz and Antony Rybovsky, a son and a grandson of Polish officers killed in western Russia's Katyn forest in 1940.
In 2005, the Chief Military Prosecutor's Office closed the Katyn case, saying those involved in the executions had since died. However, the relatives of the executed officers appealed the decision to close the case.
The Soviet Union initially accused Germany of executing the Polish prisoners. However, in 1990 Mikhail Gorbachev officially admitted that Soviet secret police were responsible for the massacre.