The video, shared via social media by ISIL sympathizers, depicts a Croatian citizen on his knees before a masked ISIL militant, with an Islamic State flag fluttering next to them.
The detainee identifies himself as Tomislav Salopek, a 30-years-old Croatian national, a former employee of the Cairo branch of French energy company CGG (General Geoscience.)
He said that if Egyptian authorities did not release the Muslim women from jails, the Islamic State fighters would behead him within 48 hours.
Islamic State is a Sunni militant in control of vast territories in Iraq and Syria. A number of ISIL cells, with local insurgent groups pledging allegiance, are also known to operate in Libya, Egypt, Afghanistan, Yemen and other territories across the Middle East and North Africa.
The ISIL militants are notorious for extreme brutality and numerous human rights atrocities including beheadings of religious minorities representatives and foreign hostages posted online.