After two purported beheadings, Islamic terrorist group ISIS has threatened to take the life of yet another hostage – 44-year old British citizen David Cawthorne Haines.

Haines had been missing since early last year, but it is only recently that new information about his abduction had surfaced. According to a report by The Independent, Haines and an Italian colleague Federico Motka were kidnapped by ISIS gunmen in northern Syria in March 2013.

It has been revealed that the two foreign national social workers, along with the witness and another companion, spent three days in the area, assessing locations for possible refugee camps. They were at the end of their assignment and were just leaving, but as they approached the Turkish border, one car overtook theirs and another one blocked the rear. Masked and armed men then threatened them.

"They knew that two of us were Syrians and they knew who else was in the car," the witness told the publication. "One of them put a gun to my head and threatened me not to tell anyone what I had seen. They put [Mr Haines and Mr Motka] in the boot of their car and shot out the tyres of our car."

Motka, according to Italian media, was freed last May after Rome authorized to pay a ransom of €6 million, a move that British Prime Minister James Cameron strongly disagrees with.

Unlike the first two hostages, Haines is not a journalist. He works for the charity organization Agency for Technical Cooperation and Development (ACTED), and is a seasoned social aid, known for helping people regardless of background or nationality. ACTED told Daily Mail that Haines is a humanitarian, and has helped people in the Middle East, Africa, and the Balkans.

Haines has a 17-year old daughter residing in Perth with his first wife, and a four-year old daughter who lives in Croatia with his current wife.