I am not sure about post WW2, but I can tell you that non-political criminals during Stalin's Purges were treated considerably better than political prisoners in prison.

While in prison, the "Vors," or "thieves-in-law," were seen as being capible of rehabilitation. They were usally given lower demand jobs like cooks, janitors, etc. Because Vors are actual criminals, they created a hierarchy in the kitchens, infirmaries, and workshops. Often times, criminals would refuse to give political prisoners necessities like food, clothing, and medicine.

Source: http://www.amazon.com/Danzig-Baldaev-Drawings-Damon-Murray/dp/0956356249

Sorry my response is so brief. I am on my mobile at work, so I can give a better answer when I get home.