David Cawthorne Haines helped those in need in some of the most hostile environments in the world.

The Scots-educated aid worker spent 11 years in the military before going to work for charities in Libya and South Sudan during periods of extreme violence, according to his LinkedIn page.

He was in Libya during its civil war in 2011, according to his online CV, working as head of mission for Handicap International, which helps disabled people in poverty and conflict zones around the world.

He spoke to MediaGlobal News while there about work he and his team were doing to prevent children being killed or maimed playing with unexploded ordnance like mortars and cluster bombs.

"Only two and a half weeks ago in Ajdabiya a child took one of these items home, and unfortunately the father decided to have a look at it and it exploded," he told the news site.

The following year he went to work for in South Sudan, which has been wracked by internal conflict since it gained independence in 2011.

He worked for the Brussels-based charity Nonviolent Peaceforce, which sends unarmed civilian peacekeepers to conflict zones.

In a statement it said he acted as a "non-partisan unarmed civilian peace facilitator" in the African state but was not working for them in the Middle East.

"We join with people around the world in pleas, thoughts and calls for his safe release," it said on its website.

Mr Haines' LinkedIn page said he attended the Perth Academy secondary school in the Scottish city.

He then held "various positions covering security and threat assessments in a number of different countries" in the military between 1988 and 1999. It did not specify which armed forces he served with.

He later combined charity work with working for private companies, most recently based in Croatia as a consultant director of an Italian-Croat catering manufacturer called Astraea.