Looking 4 Algirdas Vanagas' family
I'm looking for the family of my grandfather Olgierd (Algirdas) Vanagas, born in 1905, Riga (?), Lithuania, parents' names: Franciszek and henryka. He was a Lithuanian consul in Paris until 1939 and in 15.02.1952 died suddenly in Szczecinek (Poland) as Stefan Nowak (had to change his name due to soviet persecutions).
My grandmother - with no results - at her time through the Comite' International De La Croix-Rouge Agence Centrale Des Prisonniers De Guerre was looking for his brothers and the sister:
VANAGAS ALEKSANDER, born 1907, Riga, Lithuania, was a soviet prisoner in Riga in 1941, before lived in Riga on Dynaburg street.
VANAGAS JAN - born in Riga, was a soviet prisoner in Riga in 1941, before lived in Riga on Dynaburg street and around 1944 lived probably in Vilnius.
VANAGAS WITOLD - born in Riga, Lithuania, until 1940 lived in Riga, Dynaburg street.
VANAGAS HENRYKA - born in Riga and utill 1944 lived in Poznan (Polnad).
Any information about / from any members of my family will be very much appreciated.