He's Iraq's most notorious terrorist, with a $25m price on his head. But few know the truth about Abu Musab al-Zarqawi. Can his childishly written personal letters provide any clues?

We know he enjoys penning sweet poems in school exercise books: naive fragments edged with yellow, pink and blue drawings. What we don't know is whether Abu Musab al-Zarqawi takes an equal delight in the murderous acts that have brought him international infamy and placed a $25m bounty on his head. On these pages, his pen reveals a steady hand. Just how steady that hand was when he supposedly sanctioned the beheading of the Liverpudlian businessman Kenneth Bigley in October last year isn't clear.

That we know so little about the 38-year-old Jordanian terrorist, whose organisation "Al-Qaeda in the Land of Two Rivers" (Al-Qaeda Fi Bilad al-Rafidain) now claims responsibility for almost every bomb, beheading, hostage-taking and atrocity in Iraq, isn't surprising. Myth has always been fuelled by mystery. Whether his organisation really is responsible for all these killings is also doubtful. The latest figures show that "anti-occupation" forces have killed 2,353 people in Iraq since March 2003, 272 Iraqi civilians this month alone. But, according to figures released by Iraq's Interior Ministry, Iraqi civilians and police officers died at the rate of over 800 a month between August 2004 and this May. Most attacks were attributed to insurgents.

Which is what makes the pictures on these pages all the more chilling. The French journalist Jean-Marie Quéméner was given these letters by Zarqawi's acquaintances in Amman, Jordan. They told him they "wanted to send a message" through him "to contradict the wrong information that Jews and Americans are spreading in the world". In other words, the discovery of this correspondence was part of a none-too-subtle propaganda initiative. Quéméner and a Lebanese colleague had begun a research trip last year, and Zarqawi's contacts agreed to talk anonymously: "A meeting point was arranged at a roundabout, a car appeared and turned around, then a signal," says the journalist. "We had to follow through the labyrinth of streets until we reached a heap of sand used for construction works, and an ordinary house."

Met by three immaculately robed men, they were escorted to a comfortable room and offered coffee. Other men entered the room and, finally, according to Quéméner, "a tall man with an engraved face and a deep look appeared". He did not introduce himself, but it was clear "he was the link between Zarqawi and Al-Qaeda".

"His voice was deep and jerky, and his gestures abrupt. He talked about his 'friend' with great respect and admiration, having apparently fought with him in Afghanistan." When Quéménar asked how a gentle, affectionate man could justify the beheadings and killings of civilians in Iraq, he was told that Iraqis and Americans who collaborated with the occupational forces brought it on themselves. The room became charged with emotion as the men recalled times with Zarqawi, their "Emir". "They were telling his story; everything was mingled with the dust of the Jordanian roads, the torture in prison, the Afghanistan battles, the executions in Iraq, the guiding role of his mother," recalls Quéménar.

It was from these meetings that the journalist obtained the letters and pictures sent by Zarqawi to his mother, brother and seven sisters. It was claimed he was still sending such letters from Iraq to his family in Jordan via couriers. However, the examples here were sent when he was in prison in Jordan. Arrested in 1994, he had been sentenced to 15 years on charges of starting an illegal organisation, possessing bombs, carrying arms and verbally offending the king's honour. Five years later, after an amnesty, he was freed. Many, particularly in Iraq's Shi'ite community, believe he is dead — though this is strongly denied by those who admire him, and the burgeoning numbers of militant jihadists inspired by him. Was this meeting intended to reinforce not only his humanity, but his very existence?

In one poem, a "dedication to my mother" (she was to die from leukaemia in February 2004), decorated with a drawing of a ribbon, Zarqawi repeats a gruesome children's story in which a child is bribed to sell his mother's heart. While taking the heart to the buyer, the boy slips and falls, prompting the heart to ask: "Are you hurt, my son?" The story underscores the Islamic belief that a mother will forgive everything. On realising that his mother was still concerned for his wellbeing even after he had murdered her, the boy decides to kill himself to repent for his sin. But when he attempts to stab himself, his mother's heart calls out to him and says: "Hold your hand there. You have killed my heart once; do not kill it twice." Another letter and poem sent to one of his sisters and his brother-in-law, and signed "your guilty brother — the Stranger", asks both of them to pray for him and for God to forgive him if he has erred.

It would be dangerous to read too much into these partial, propaganda-inspired texts. Most appear to be typical of the personal notes any Muslim prisoner might send to their families. Robert Pape of the University of Chicago, whose recent book Dying to Win draws on a detailed study of terrorists, argues that such expression of feelings among suicide terrorists and their leaders is common. He suggests that one passage may be of significance. "Here he worries that powerful non-Muslims will use their power to attack and convert Muslims to another religion, presumably including himself. This helps to explain why he'd be so fearful that western combat forces in Iraq and the Arabian peninsula in general pose an urgent threat to his community. This reflects the similar sentiment in the opening paragraphs of his famous letter to Osama Bin Laden in 2004, in which he said the American military has come to Iraq to create the conditions that would enable the second coming of the Christian Messiah."

A poor scholar and a heavy drinker, Zarqawi dropped out of school and is remembered in his Jordanian home city as a rebellious, violent teenager, though he came from a well-respected Bedouin family. His deeply religious mother, anxious to put him back on the right path, enrolled him for religious instruction at a mosque in Amman known for its Salafist stance. From there, in 1989, he went to Afghanistan, where he became involved with the jihad.

Zarqawi's real name is Ahmad Fadil Nazzal al-Khalayleh, though he has operated under a number of aliases. His most recent incarnation began in the early 1990s, after training in Afghanistan. Returning home to Zarqa, he assumed the new name to reflect his ambition to represent his city. Musab is borrowed from one of the prophet Muhammad's warriors, an inspiration for suicide bombers.

His continued campaigning led to his arrest and imprisonment in 1994. Following his release from prison, the hardened Jordanian Islamist set off for Pakistan, finally leaving his family, past life and country behind. Based in Hayatabad, on the outskirts of Peshawar, near the Afghanistan border, a nerve centre for Al-Qaeda, Zarqawi's return coincided with Al-Qaeda's rise. He forged a friendship with Bin Laden and even sought funding from him, but worked on establishing his own network and organisation, under the name Tawhid wal Jihad — Unity and Holy War. (He renamed it Al-Qaeda in the Land of Two Rivers in October 2004.) He resurfaced in Iraq in 2002, where he aligned himself with Ansar al-Islam, another radical Salafist movement, and made his way to Baghdad after the fall of Saddam Hussein. He remains in hiding to this day.

Whoever the real Zarqawi is, he is dwarfed by Zarqawi the legend. Somewhere along the line, Zarqawi the man has disappeared.