The soldiers, who were targeted by insurgents as they travelled through the country, died after being attacked with bombs triggered by infra-red beams. The bombs were developed by the IRA using technology passed on by the security services in a botched "sting" operation more than a decade ago.
This contradicts the British government's claims that Iran's Revolutionary Guard is helping Shia insurgents to make the devices.
The Independent on Sunday can also reveal that the bombs and the firing devices used to kill the soldiers, as well as two private security guards, were initially created by the UK security services as part of a counter-terrorism strategy at the height of the troubles in the early 1990s.
According to security sources, the technology for the bombs used in the attacks, which were developed using technology from photographic flash units, was employed by the IRA some 15 years ago after Irish terrorists were given advice by British agents.
"We are seeing technology in Iraq today that it took the IRA 20 years to develop," said a military intelligence officer with experience in Northern Ireland.
He revealed that one trigger used in a recent Iraqi bombing was a three-way device, combining a command wire, a radio signal and an infra-red beam - a technique perfected by the IRA.
Britain claims that the bomb-making expertise now being used in southern Iraq was passed on by Iran's Revolutionary Guard through Hizbollah, the revolutionary Islamist group it sponsors in Lebanon.
But a former agent who infiltrated the IRA told The Independent on Sunday that the technology reached the Middle East through the IRA's co-operation with Palestinian groups. In turn, some of these groups used to be sponsored by Saddam Hussein and his Baath party.
The former agent added: "The photographic flashgun unit was replaced with infra-red and then coded infra-red, but basically they were variations of the same device. The technology came from the security forces, but the IRA always shared its equipment and expertise with Farc guerrillas in Colombia, the Basque separatists, ETA and Palestinian groups. There is no doubt in my mind that the technology used to kill our troops in Basra is the same British technology from a decade ago."
Even more alarming is the claim that the devices were supplied by the security services to an agent inside the Provisionals as part of a dangerous game of double bluff.
According to investigators examining past collusion between the security forces and paramilitaries in Northern Ireland, members of the shadowy army undercover outfit, the Force Research Unit, and officers from MI5 learned in the early 1990s that a senior IRA member in south Armagh was working to develop bombs triggered by light beams. They decided the risks would be diminished if they knew what technology was being used.
"The thinking of the security forces was that if they were intimate with the technology, then they could develop counter-measures, thereby staying one step ahead of the IRA," a senior source close to the inquiry explained. "It may seem absurd that the security services were supplying technology to the IRA, but the strategy was sound.
"Unfortunately, no one could see back then that this technology would be used to kill British soldiers thousands of miles away in a different war."
The Provisionals' agent was allowed to travel to New York andpurchase the equipment. But the strategy backfired in March 1992 when the technology triggered a bomb that killed a policewoman and mutilated her male colleague near Newry before counter-measures were in place.
* A dossier naming the alleged killers of the six Red Caps murdered by an Iraqi mob more than two years ago is being handed over to Iraqi judges this week. The six members of the Royal Military Police were butchered to death in June 2003 in an Iraqi police station after being attacked by about 300 tribesmen.
* Two mothers of British soldiers killed in Iraq are to stage a 24-hour "peace camp" opposite Downing Street on Tuesday.Reuse content