This claim comes from
this interview with Amy Zahl Gottlieb. Gottlieb was involved in helping Jewish refugees in Egypt and Greece. She said the Greek Jews came back from camps with these tattoos.
We had girls who came back who had tattooed across their stomachs, "Nur für Offizieren" "Only for officers". They were used in brothels. The boys, very many of them, had been castrated. [...] As I mentioned earlier, I remember very clearly, the population among Jews in Greece had been 70,000 before the war, and after the war there were 10,000. That's a tremendous percentage of Jews who were killed.
Q: Were most of the people who came back from the concentration camps from Auschwitz, or from labor camps that they had been sent to on death marches?
A: They were from different concentration camps. I don't think any of them had been in labor camps. I think they were in concentration camps, which were death camps.
Q: This young girl that you said was had a tattoo on her that said, "Only for officers", was she a Jewish girl?
A: Oh, yes, I'm talking about the Jews. There was some non-Jews who came back to Greece. I must say we helped them, too, where we could. We didn't differentiate. For the most part, it was Jews who were deported.
Needless to say, there shouldn't have been many if any survivors if they came exclusively from
death camps, as she claimed.
The bit about tattoos seems unique and lacking corroboration. Is it made up? It doesn't help that even the interviewer somehow misinterpreted Gottlieb's description of "girls" (plural) as referring to a "young girl" (singular).
The bit about castration also seems made up. As it is with the details given in so many of these Holocaust oral histories.