Welcome to the site Noel. Basic information on some of the so called "Special Camps" is available, but detail is not readily available, at lest not in English. The NKVD kept many prisoners in the Soviet zone of occupation in former Concentration Camps. For instance Sachsenhausen Concentration Camp was Special Camp Number 7 (later renamed Special Camp #1).
There is a man named Alex Latotzky who was born in one of the camps in 1948. He has a site at
a childhood behind barbed wire. You may want to use the contact link there to see what information he has.