And while using the map site I listed above, I have found that the region around Borne Sulinowo/Kłomino hosted some WW2 German prison camps, particularly for French and Polish officers.
An officers camp, Offizier Lager in German, shortened to Oflag was quite close to the site of Kłomino and its cemetary can be found on the map - cmentarz oflagu IID - when you use the OpenStreetMap option, located slightly west-south-west of Kłomino.
There's a Polish wiki page for the prison camp here:
https://pl.wikipedia.org/wiki/Oflag_II_D_Gross-Born
And there's also this site:
http://www.s225821866.onlinehome.fr/...Gross-born.php
Again for both, you'll have to translate the pages if you don't speak Polish or French