A crypto jew maybe, but I would research to see if he is a sabbatean jew. These are ones that everyone should look out for. The Sabbateans were a variety of Jewish followers, disciples, and believers in Sabbatai Zevi, a Sephardic Jewish rabbi and Kabbalist who was proclaimed to be the Jewish Messiah in 1666 by Nathan of Gaza. Vast numbers of Jews in the Jewish diaspora accepted his claims, even after he outwardly became an apostate due to his forced conversion to Islam in the same year. The Dönmeh were a group of Sabbatean crypto-Jews in the Ottoman Empire who converted outwardly to Islam but retained their Jewish faith and Kabbalistic beliefs in secret. The movement was centered mainly in Thessaloniki.