The Italian journalist who launched the controversy over the American use of white phosphorus (WP) as a weapon of war in the Fallujah siege has accused the Americans of hypocrisy.

Sigfrido Ranucci, who made the documentary for the RAI television channel aired two weeks ago, said that a US intelligence assessment had characterised WP after the first Gulf War as a "chemical weapon".

The assessment was published in a declassified report on the American Department of Defence website. The file was headed: "Possible use of phosphorous chemical weapons by Iraq in Kurdish areas along the Iraqi-Turkish-Iranian borders."

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In late February 1991, an intelligence source reported, during the Iraqi crackdown on the Kurdish uprising that followed the coalition victory against Iraq, "Iraqi forces loyal to President Saddam may have possibly used white phosphorous chemical weapons against Kurdish rebels and the populace in Erbil and Dohuk. The WP chemical was delivered by artillery rounds and helicopter gunships."

According to the intelligence report, the "reports of possible WP chemical weapon attacks spread quickly among the populace in Erbil and Dohuk. As a result, hundreds of thousands of Kurds fled from these two areas" across the border into Turkey.

"When Saddam used WP it was a chemical weapon," said Mr Ranucci, "but when the Americans use it, it's a conventional weapon. The injuries it inflicts, however, are just as terrible however you describe it."

In the television documentary, eyewitnesses inside Fallujah during the bombardment in November last year described the terror and agony suffered by victims of the shells . Two former American soldiers who fought at Fallujah told how they had been ordered to prepare for the use of the weapons. The film and still photographs posted on the website of the channel that made the film - rainews24.it - show the strange corpses found after the city's destruction, many with their skin apparently melted or caramelised so their features were indistinguishable. Mr Ranucci said he had seen photographs of "more than 100" of what he described as "anomalous corpses" in the city.

The US State Department and the Pentagon have shifted their position repeatedly in the aftermath of the film's showing. After initially saying that US forces do not use white phosphorus as a weapon, the Pentagon now says that WP had been used against insurgents in Fallujah. The use of WP against civilians as a weapon is prohibited.

Military analysts said that there remain questions about the official US position regarding its observance of the 1980 conventional weapons treaty which governs the use of WP as an incendiary weapon and sets out clear guidelines about the protection of civilians.

Daryl Kimball, director of the Arms Control Association in Washington, called for an independent investigation of the use of WP during the Fallujah siege. "If it was used as an incendiary weapon, clear restrictions apply," he said.

"Given that the US and UK went into Iraq on the ground that Saddam Hussein had used chemical weapons against his own people, we need to make sure that we are not violating the laws that we have subscribed to," he added.

Yesterday Adam Mynott, a BBC correspondent in Nassiriya in April 2003, told Rai News 24 that he had seen WP apparently used as a weapon against insurgents in that city.