https://collections.arolsen-archives.org/en/document/6462329
typo? - camp stamp „Merzweiler“ (Nierzweiler?) should most likely read „Natzweiler“
According to this document he was transferred to Natzweiler on 24.10.1941 (prisoner no 469)
#belgian
Joannes Theophiel LEFFELAER (*17.02.1910)
He died in Natzweiler on 02.06.1942
arolsen-archives
zooniverse ENC, thanks to @velthove1