Details have begun to emerge about the British hostage who appeared in a video purportedly showing the beheading of American journalist Steven Sotloff.

David Cawthorne Haines appeared at the end of the video released by the Islamic State (formerly Isis), after a segment which apparently showed the final moments before Sotloff's beheading. Like Sotloff, Hayes was kneeling on the ground wearing orange prisoners' robes.

It is now being reported that Haines is a former soldier who left the British armed forces in 1999 and provided security services for several aid organisations before being abducted in Syria in early 2013.

Tiffany Easthom, the South Sudan country director of civilian peacekeeping organisation Nonviolent Peaceforce, told NBC News that Haines worked for them prior to his capture, adding: "A fellow he was abducted with was released a couple of months ago, and we were hopeful that he would be released soon."

Easthom described Haines as being "very familiar with insecure locations", adding that he was "very caring, with a good sense of humour."

On his LinkedIn page, Haines reveals he attended Perth Academy in Scotland and lists himself as consultancy director for a Croatian-based manufacturing firm called Astraea. In the 15 years since he left the forces, he appears to have worked extensively in the Balkans; one of his most significant roles was at ASB, a German firm which undertook major humanitarian work in the region during the 1992-95 Balkan war.

In addition to his work in the former Yugoslavia, Haines has worked for a peace force in South Sudan and headed up a mission for refugee aid organisation Handicap International.

Haines married a Croatian woman, Dragana Prodanovic Haines, in 2010, and they apparently have one daughter together.