An employee of a French company, Salopek was kidnapped on July 22 on a road 22km south-west of Cairo. On Friday the "Sinai Province" group threatened to kill the hostage within 48 hours if the Egyptian government failed to free Muslim women imprisoned in Egypt.

There has been no independent verification of the photo, which included a caption reading: “killing of the Croatian hostage, due to his country’s participation in the war against Islamic State, after the deadline expired,” Euronews reported on Wednesday.

Last week a video posted online purportedly from Sinai Province showed a man identifying himself as Salopek who said that he would be killed if Muslim women weren’t released from Egyptian jails.