[6] After the Winter War, the Soviet POWs were returned to the USSR in accordance with the Moscow Peace Treaty.
[3] The first Soviet POWs were taken in June 1941 and were transferred to reserve prisons in Karvia, Köyliö, Huittinen and Pelso (a village in modern-day municipality of Vaala).
Soon Finnish administration realized that the number of POWs was much greater than initially estimated, and established 32 new prison camps in 1941–1944.
[10] There was a shortage of labour in Finland and authorities assigned POWs to forest and agricultural work, as well as the construction of fortification lines.
[14] In the subsequent study by Professor Heikki Ylikangas it turned out that about 2,000 of the exchanged prisoners joined the Russian Liberation Army.
The rest, mostly army and political officers, (among them a name-based estimate of 74 Jews), most likely perished in Nazi concentration camps.
Prisoners died due to bad camp conditions and the poor supply of food, shelter, clothing, and health care.
[20] Hostilities between Finland and the Allied powers of the United Kingdom and the Soviet Union were suspended following the Moscow Armistice.
This agreement (whose execution was specifically delegated to the Soviet High Command on behalf of the Allied powers) further stipulated the conditions necessary for Finland to conclude a final peace treaty.
The Finnish parliament had to create ex post facto laws for the trials, though in the case of war crimes the country had already signed the Hague IV Convention.
[21] In short, Finland had to simultaneously arrange its own independent investigations and trials, and report them for verification to the Soviet Union.
[22] Criminal charges were filed against 1,381 Finnish POW camp staff members, resulting in 723 convictions and 658 acquittals.
[26] Finland had signed the 1907 Hague IV Convention in 1922 that covered the treatment of prisoners of war in detail.