Cairo - An Egyptian prosecution official said on Saturday authorities were probing the death of a man at a police station, after a Coptic Church bishop said he had been beaten to death.
The 50-year-old Coptic Christian Magdy Makin, a fish vendor, had been detained in a police station before his family received his corpse on Monday.
"The body showed clear signs of torture," his son Malak Magdy Makin told AFP.
"We are waiting for the forensic report to determine whether his death was natural or criminal," said prosecution official Adham Montasser.
Coptic Bishop Makarios had on Friday charged that Makin was tortured to death.
He said on his Facebook page that he visited Makin's family to express his condolences after the man died "as a result of ugly torture."
There have been a string of deaths, allegedly by torture, in Egyptian police stations that have sparked anger and led to the trials of several policemen.
The interior ministry says such abuses are an exception and that police do not practice torture.
President Abdel Fattah al-Sisi has pledged to hold accountable errant policemen.
Police abuses had helped fuel a 2011 uprising that unseated veteran strongman Hosni Mubarak.