Martin,
His familyname was BIELFELDT (not BIELEFELDT) and his first names Johan Pieter Jurgen. Go to:
http://www.ogs.nl, klick on 'Slachtofferregister', write behind 'Achternaam' (= Familyname) Bielfeldt and behind 'Voorletters' (= Initials) J.P.J. (with dots). Klick on 'Zoeken' (= Search) and klick on his family name Bielfeldt.
At your service,
Henk.