@Sviatogor Poles from the Ukraine usually are from western ukraine and dont usually cluster with mazovian poles. I think he must have some mazovian or belarusian ancestry as his last name is found in belarus as you mentioned. He has no knowledge of this though which is strange. Maybe his mother or one of his grandparents had an affair with a soviet soldier or something. Who knows, its very interesting though. I would have to have more samples from spis and surrounding areas.