Tracing survivors of concentration camps in Poland... Is this possible?

[bigknickersbigknockers]

My father in law has recently passed away. He was born in Poland and came to this contry during the war. He left behind his parents and 2 brothers and sadly never saw them again. In the 1970s He and his family travelled back to Poland to his home town to try and trace any surviving family though they never found anyone. In the weeks following my FILs funeral a photo of his brother has turned up and his children would really like to know once and for all what happend to his family... did they die in the death camps or did any of them survive. Is it possible to find out without having to spend massive amounts of money on travelling and if so how could they go about this? TIA

My membership has lapsed now but I am pretty sure Ancestry has lists from at least some of the camps. Are you a member?

No Im not a member mole, this is my first line of enquiry. I really have no idea where to start.

Here are some of the records Ancestry holds:

Germany: Dachau Concentration Camp Records, 1945 Military 168,116
Germany: Flossenbürg Concentration Camp Records, 1938-1945 Military 88,367
Austria: Mauthausen/Gusen Concentration Camp Death Record Books , 1938-1945 Birth, Marriage & Death 38,207
World War II Japanese-American Internment Camp Documents, 1942-1946 Court, Land, Wills & Financial 89,390
Holocaust: Auschwitz Forced Laborers Military 5,310
Camp Travis, Texas World War I Records Military 19,949
France: Natzweiler-Struthof Concentration Camp Record Book, 1940-1945 Military 33,722
Holocaust: Survivors listed in a Hungarian Periodical, 1945 Military 17,931
Holocaust: Schindler's Lists Directories & Member Lists 1,980
Holocaust: Łódż (Poland) Transports to Chelmo (Kulmhof) Camp, 1944 Birth, Marriage & Death 7,168

Might the Shoah Victims' Database provided by Yad Vashem be a good starting point? Good luck.

Have you tried the Red Cross?

Thanks for the help, apparently FILs brother was conscripted into the German navy and spent time in Dieppe (France) I suppose there is every possibility that they didnt end up in concentration camps but have no idea where to start. It doesnt help because the details are sketchy to say the least so I think it may be very difficult if not impossible to find out exactly what became of them. FIL did contact the red cross in the early 1970s and they wrote back wanting more details. He never wrote back... MIL says he was afraid of finding out that they hadnt survived or that they did and were living in poverty as most of Poland was at the time. He could be quite stubborn so that was that so to speak, though as I said in OP they did travel to Poland and found nothing.