Photo of William Henderson's IDs and Passport as released on ABM's twitter account last Sunday
The Sinai based militant group Ansar Beit Al-Maqdis has taken responsibility for killing a US citizen in Egypt's Western Desert in August of this year.
Ansar Beit Al-Maqdis, which recently pledged allegiance to the Islamic State and changed its name to the Sinai Province, said on its social media sites that it had abducted and killed US citizen William Bill Henderson, 58, a production expert working for Texas-based Apache energy company in the Western Desert.
The militant group published photos of Henderson's US passport and two ID cards issued by Apache and Qarun Petroleum, a joint venture between Egypt and a group of foreign oil companies including Apache.
On 11 August, Egyptian security officials announced that one of Apache's American employees had been killed by gunfire while driving between Qarun and Karama in the Western Desert.
The officials didn't provide any details about the employee's identity, adding that his body had been found in the road with another foreigner who had been working with Qarun Petroleum and whose identity was also not revealed.
The Oklahoma-based news website Enid News and Eagle published an obituary on 14 August for Anderson, saying he was born on 12 January 1956 and died suddenly while working for Apache Corp in Karama, Egypt.
Apache owns several natural gas facilities in Egypt's Western Desert, including ones in Karama and Qarun, southwest Cairo. Foreign oil and gas companies work in Egypt under production sharing contracts with the Egyptian government.
This is the first time Ansar Beit Al-Maqdis has claimed responsibility for abducting and killing a foreigner in Egypt.
Egyptian and US officials haven't commented yet on the announcement.
The militant group has claimed several main terror attacks in Egypt since the ouster of president Mohamed Morsi in July 2013, including an attempt in September to assassinate the interior minister and several attacks targeting security headquarters and convoys.