I hadn't heard that, exactly, but I had heard both story and testimony of the discovery of what could only be called "children brothel / abattoirs." A Russian soldier who was recounting what he saw was nearly without words, being so distracted by the horrible memory. He was still in a state of shock. I suspect these discoveries, along with collateral orphans, made up the much-denounced thousands of children that were removed to Russia...where they would be safe.