From: Rabbi Moshe Sofer
To: Unknown recipient
A circumcised soldier died in a military hospital in a Muslim land with a Christian pendant around his neck, raising questions about whether the Jewish burial society was obligated to arrange his burial and whether he could be interred in a Jewish cemetery. The Chasam Sofer rules that the community was obligated to arrange burial, since the certainty of Jewish birth evidenced by circumcision cannot be overturned by the mere doubt raised by the pendant, and multiple additional arguments including a double doubt support the obligation. However, he expresses reservations about burying the man among the fully righteous, though since the burial has already taken place, exhumation should not be performed as the burial itself may have provided atonement.
Source: Shu"t Chasam Sofer YD §341