Is 'Filreis' Portuguese?

In 2003 I corresponded with the cultural director of a Portuguese foundation. He responded to the possibility that my family’s name is indeed Portuguese. I’m not sure what the origin of this family assumption is — perhaps it’s been passed down to my father’s older brother through his father or his brother who passed through western Europe on the way to Brooklyn twice in the 1910s and ’20s (once before WWI and once again after). Western Europe — France, we assume — where one of these Filreises made contact with French or Spanish/French Filreises and learned of the ancestral connection to Iberian peninsula. We put that “news" together with the clear sense that the families were part of a Sephardic community in Warsaw and have assumed that they were part of the exilic migration away from Spain to northeast Europe in the late fifteenth and early sixteenth centuries. It is very difficult to track this, but since Jewish families typically bred very closely within the Jewish community, there is probably a way of following the lineage. I haven’t figured out how yet. I suppose first would be to find out definitely where the members of the Warsaw family were killed during the Holocaust; I’m 99% sure it was at Treblinka, the killing camp that destroyed Warsaw’s Jews in 1942 and ’43.