THE bland name gives nothing away, like the unit itself, but the Iraq Survey Group, and its 1,200 experts on weapons of mass destruction, are what Tony Blair is depending on to find Iraq’s elusive arsenal and save his credibility.

The group is a specialist unit, made up of American, British and Australian military and other civilian agency personnel.

It was appointed in late May in what the Pentagon called a “significant expansion” of the so-far fruitless hunt for Saddam Hussein’s weapons of mass destruction.

Its headquarters is located on the outskirts of Baghdad, near the vast, high-security military area that is Baghdad International Airport, but unlike the United Nations’ prewar weapons inspection teams it hardly advertises its presence.

As one military official put it, the group is “not terribly forthcoming” about its work.

Back in London, government sources insisted yesterday that the group was steadily amassing evidence proving the existence of programmes to develop weapons of mass destruction.

They said that the investigators had already uncovered a substantial amount of documents, equipment and suspect material, and they expressed confidence that the Government’s September dossier would be “substantiated in the main”.

But they also said that the investigation would continue for several more months and were wary of making any public claims until they could present a detailed picture.

American defence officials were also optimistic. “It’s going to be a complex, long task, but in the end the truth will out,” one said. “We remain confident that the evidence will be compelling.”

Republican senators who returned from a visit to Iraq last week promised imminent revelations, although their Democrat counterparts were less sanguine. Pat Roberts, of Kansas, said: “My judgment is that there is going to be breaking, positive news on that front in the very near-term.”

But for now, such statements must be taken on trust, because the group is giving little away. Its only known breakthrough came when an Iraqi scientist admitted that he had been told to bury components of a nuclear bomb in his garden 12 years ago. Mahdi Obeidi dutifully handed over to US officials parts for a centrifuge system for enriching uranium.

The unit is headed by Major-General Keith Dayton, director of operations for the US Defence Intelligence Agency. He has a British deputy, Brigadier John Deverell.

The unit has offices in Baghdad, Washington and Qatar, where 120 analysts and 250 processers advise and monitor the work going on inside Iraq. About a hundred of the group’s members are British.

Unlike its predecessor, the much smaller 75th Exploitation Task Force, the group has not set out to scour all 900 “suspect sites” spread across Iraq and identified before the war. Instead, equipped with mobile laboratories, its staff study the reams of data recovered from Iraqi officials, institutions and intelligence sources. They then dispatch mobile site survey teams to particular locations.

One military source in Baghdad said: “The way the XTF operated was that if someone tripped over a site they would come along and do an analysis. The ISG is much more intelligence-led.

“There is a lot of analysis and document searches that produce leads, which other units then go out and check.

“Rather than wade through the haystack trying to find the needle, they devote their effort to trying to find people who can tell you where the needle is.”

Guards or lorry drivers who witnessed comings and goings at suspect sites might be more helpful than higher-level figures “who may not want to tell us anything”, General Dayton said.

As members of the survey group descend on a village where possible witnesses live, they will be accompanied by specially trained interrogators, military and civilian, to extract information from the Iraqis.

“Things could have been either taken or buried, they could have been transported, or they could have been destroyed,” General Dayton said. “That’s the assumption I’m going in on.”

The group’s headquarters has joint interrogation, debriefing and material exploitation centres, chemical and biological intelligence support teams and an operations centre. Military sources revealed that it has “virtual reality” capabilities that allow it to draw upon the nuclear, chemical and biological weapons expertise of British and American institutions including Porton Down, the biochemicals research centre near Salisbury.

The unit reports directly to US Central Command based in Florida and is operating independently from Paul Bremer’s Coalition Provisional Authority.

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