Art. 4. The government of the USSR declares its consent for the creation on the Soviet Union's territory of a Polish Army whose commander will be appointed by the Polish government in consultation with the government of the USSR. [...]
As from the moment of restoration of mutual diplomatic relations the Soviet government grants amnesty to all Polish citizens who are currently deprived of freedom on the territory of the USSR either as prisoners of war or under other relevant rules.
London, July 30, 1941
Stosunki Rzeczypospolitej Polskiej z państwem radzieckim 1918-1943. Wybór dokumentów (Poland's Relations with the Soviet State in 1918-1943. Selected Documents), ed. Jerzy Kumaniecki, Warsaw 1991