DHAKA: A video has been released on the internet that purports to show an ISIL fighter beheading British hostage Alan Henning, the fourth such killing carried out by the Sunni-led armed group now being targeted by US-led air strikes.

The video, released on Friday, begins with a news clip announcing British strikes against ISIL, or the Islamic State of Iraq and the Levant.

News agencies could not immediately verify the video's authenticity, though it was released in the same manner as other ISIL videos and the masked man sounded similar to the one who carried out the other slayings, reports Al-Jazeera.

Henning, 47, nicknamed "Gadget", had joined an aid convoy and was taken captive on December 26, shortly after crossing the border between Turkey and Syria.

Earlier this week, Henning's wife Barbara Henning asked ISIL in a televised plea: "Please release him. We need him back home."

In a statement, the British Foreign Office said it was working to verify the video.

"If true, this is a further disgusting murder," the statement read. "We are offering the family every support possible; they ask to be left alone at this time."

Britain has been supporting U.S military efforts against ISIL by using British forces to help with logistics and intelligence gathering, as well as recently taking part in air strikes in Iraq.

BDST: 0912 HRS, OCT 04, 2014