Some Soviet POWs who survived German captivity were accused by the Soviet authorities of collaboration with the Nazis or branded as traitors under Order No. 270, which prohibited any soldier from surrendering. During and after World War II freed POWs went to special "filtration camps". Of these, by 1944, more than 90 per cent were cleared, and about 8 per cent were arrested or condemned to serve in penal battalions. In 1944, they were sent directly to reserve military formations to be cleared by the NKVD. Further, in 1945, about 100 filtration camps were set for repatriated Ostarbeiter, POWs, and other displaced persons, which processed more than 4,000,000 people. By 1946, 80 per cent civilians and 20 per cent of POWs were freed, 5 per cent of civilians, and 43 per cent of POWs were re-drafted, 10 per cent of civilians and 22 per cent of POWs were sent to labor battalions, and 2 per cent of civilians and 15 per cent of the POWs (226,127 out of 1,539,475 total) were transferred to the NKVD, i.e. the Gulag.
Russian historian G.F. Krivosheev gives slightly different numbers based on documents provided by the KGB: 233,400 were found guilty of collaborating with the enemy and sent to Gulag camps out of 1,836,562 Soviet soldiers who returned from captivity. Latter data do not include millions of civilians who have been repatriated (often involuntarily) to the Soviet Union, and a significant number of whom were also sent to the Gulag or executed (e.g. Betrayal of the Cossacks). The Black Book of Communism provides different numbers: 19.1% of ex-POWs were sent to penal battalions of the Red Army, 14.5% were sent to forced labour "reconstruction battalions" (usually for two years), and 360,000 people (about 8%) were sentenced to ten to twenty years in the Gulag. The survivors were released during the general amnesty for all POWs and accused collaborators in 1955 on the wave of De-Stalinization following Stalin's death in 1953.
While many scholars agree that de-classified Soviet archive data is a reliable source, Rolf-Dieter Müller and Gerd R. Ueberschär claimed "Soviet historians engaged for the most part in a disinformation campaign about the extent of the prisoner-of-war problem." and that almost all returning POWs were convicted of collaboration and treason hence sentenced to the various forms of forced labour, while admitting that it would be unlikely to study the full extent of the history of the Soviet prisoners of war. Thousands of Soviet POWs indeed survived through collaboration, many of them joining German forces, including the SS formations.