The body of Robert Kuwalek, one of Poland’s foremost Holocaust scholars, was found days after he had been reported missing in Ukraine.

Kuwalek, 47, had been reported missing Thursday while on a visit to Lviv. His body was found over the weekend.

The Polish consulate in Lviv confirmed his death, but no details about the cause of death were released.

Kuwalek, who was not Jewish, was an expert on the Holocaust in southeastern Poland and what is now western Ukraine. Based in Lublin, Kuwalek was a curator and educator at the State Museum at the former Majdanek concentration and death camp and also had served as director of the museum at the former Belzec death camp.

He published widely on topics relating to the Holocaust and also on Jewish heritage and history.