He had tried to come home just days before his capture

Mystery surrounds the circumstances in which Nick Berg ended up in the hands of his killers.

Described by his family in Philadelphia as an idealistic adventurer, he had gone to Iraq in the hope of being able to help rebuild the country. However, when he turned up in March, the job he was expecting had not materialised, so he set off to see the country.

Ironically, Mr Berg, who ran his own communications business, had been looking forward to a reunion with his family only days before his capture.

He had intended making his way home through Jordan, Turkey or Kuwait. But at the end of March he was detained by Iraqi police at a checkpoint in Mosul amid confusion as to what he was doing in the area. He was then passed to the US military who held him for 13 days.

It was only when his parents sued the federal government for his release on 5 April that he was freed. How and why he was captured by the terrorists is not known.

His parents believe it was this delay which meant he was unable to begin his journey home. At his home in West Chester, a suburb of Philadelphia, his father Michael said he had travelled in the Third World before, including visits to Kenya and Ghana, where he had spent £500 on a brick press for an impoverished village.

His family had not wanted him to travel to Iraq but he would call home every day, and sent regular emails to reassure his parents and brother and sister that he was safe and well. But they last heard from him on 9 April and their concern started to mount.

Mr Berg's parents think he was lured partly by a sense of adventure, partly because he was a "staunch supporter of the government position in Iraq and he wanted to go over there and help". His mother, Suzanne, said: "He had this idea he could help rebuild the infrastructure."

Mr Berg,who would happily risk his life by clambering up pylons and gantries to find faults, first went to Iraq on 21 December. He stayed until 1 February, making contacts with a company that indicated there would probably be work for him later. He returned on 14 March but there was no work, so he began travelling.

Friend Dave Skalish said: "He was a survivor who could pretty much deal with whatever came his way."