When you follow legal procedure (acc. the law you have right to get any ascendants certifate birth/marr./death which are not available in "public circulation") you have to prove fact that you descendant.

Not "relative" - descendant (or siblings).
You are loking for birth records of Edward Ruta ...

Urząd Stanu Cywilnego w Białowieży ul. Sportowa 1
17-230 Białowieża +48856812257

Problem is not in language:( You hahe to finf way to confirm your ID and fact that you are the grandson

I have a copy of his British passport (became a citizen in the 70s) and a copy of his baptism certificate but ...

Ok, thank you. At the moment just looking for by grandfather's record of birth (1927), but will certainly look into Narew afterwards for more family information, thank you.

Forgive me, I don't speak Polish, do you have any pointers of how I can find the birth record?

earlier (before) par. Narew
https://parafie.genealodzy.pl/index.php?op=pr&pid=5385
https://pl.wikipedia.org/wiki/Parafia_Wniebowzięcia_Najświętszej_Maryi_Panny_i_św._Stanisława_Biskupa_i_Męczennika_w_Narwi
(AD Drohiczyn)

Hi, are you saying that is the church where he was baptised? I thought it ...

I'm searching for the birth records and any related family records for the late Edward Ruta, a relative. The only document I have is a baptism record that states he was baptised in Bialowieza, presumably Saint Teresa of the Child Jesus on 6/6/1927. I don't know for sure that he was born in ...