Records of deaths in Poland by the Gestapo WWII

[Domenica007]

My great grandparents, Michael and Domenica Gaj, lived in Poland, and were killed by the Gestapo during WWII, approx. 1940-1941.
I do not speak Polish so have no clue where to look for a record of their deaths, if in fact there is a record at all.
I have heard that the Red Cross kept records of Poles killed by the Germans but I'm not sure if that is true.

[Jomot]

The following website might be of some help: 

http://www.crarg.org/

I found only three references to the name Gaj but all survived, although there is also a reference to a Mechel GAJER from Laszczow who, with wife, & daughter (unnamed), ended up in Russia. It does say you can write and ask if they have records of your family though so there could be something they have but not put online.

[Rudolf H B]

"Memory of the World"

The International Tracing Service The International Tracing Service (ITS) in Bad Arolsen is a centre for documentation, information and research on Nazi persecution, forced labour and the Holocaust. The ITS archives document the fate of millions of victims whose names and memory are to be preserved.

https://www.its-arolsen.org/en/homepage/index.html (English Version)

[Domenica007]

thanks Jomot for the useful link to crarg.org, however my great grandparents were not Polish Jews, and this seems to be specifically used for researching Jewish Holocaust victims from Poland. My great grand parents were just Polish farmers who were killed by the Gestapo in 1941. My grandfather, Piotr, received a letter from the Red Cross sometime in 1941 when he was stationed at Hemswell, Lincolnshire, as an RAF Pilot, informing him of his parents deaths.
Thank you for you help and apologies for taking so long to respond, I only just logged in here again after a long break.

[Domenica007]

Also thank you Spotz for the info on the tracing international records, very useful.