The Red Cross has a migration advice line you can call to that works with questions concerning family reunification. They also work with tracing of lost family members.
Migration advice line:
Phone number: +46 (0)20- 41 50 00
We are open Tuesdays, Wednesdays and Thursdays 09.30-12.00.
Because of the nature of family reunion cases it is important to call us, we are unable to answer your questions about your case by e-mail.
You can also read more about what we can do within family reunification on our website here: https://www.xn--rdakorset-07a.se/fa-hjalp/stod-vid-familjeaterforening/