Dear Ms. Passieu,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located a few series of records that contain some records relating to German POWs here and here. For access to and/or questions about these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at archives2reference@nara gov. Please include your uncle’s first and last name, his date of birth and place of birth in the email..
The personnel records of World War II German Prisoners of War (POWs) were returned to Germany and can be accessed through the Deutsche Dienststelle (WASt).
We hope this information is helpful. Best of luck with your family research!