NEW YORK, Feb 26: An analysis of suspected radioactive substances seized in Afghanistan has found nothing to prove that Osama bin Laden reached his decade-long goal of acquiring nuclear material for a bomb, the New York Times said on Tuesday, quoting Bush administration officials.

The analysis of suspicious canisters, computer discs and documents conducted by the government suggests that Osama and Al Qaeda network may have been duped by black-market weapons swindlers selling crude containers hand-painted with skulls and crossbones and dipped, perhaps, in medical waste to fool a Geiger counter, officials told the paper.

American officials also told the paper that the United States has yet to find evidence that Al Qaeda was able to create a chemical or biological weapon at any of its camps, command centres or caves in Afghanistan.

More than 110 government buildings, military compounds, terrorist camps, safe houses and caves in Afghanistan have been searched for clues about Al Qaeda’s plans and development of advanced terror weapons.

American intelligence officers and Special Forces found three containers with contents worrisome enough to be shipped back for detailed analysis by nuclear scientists, the paper said.

No significant amount of radioactive material was found in the containers, two seized at the ministry of agriculture in Kabul and one at an Al Qaeda compound in the Kandahar region, officials said.

“We did not find any type of serious radiological material,” one Pentagon official said. “The stuff we found in Afghanistan was not the real stuff. They were swindled, like a lot of other people.”

Another administration official who has been briefed on the material seized in Afghanistan said, “Their value for a weapon was zero.”

However, despite the analysis and Al Qaeda’s rout from Afghanistan, the group still has the desire, resources and global network of operatives to seek and, perhaps someday, acquire nuclear materials, or biological or chemical ones, that could be used in a terror attack, officials told the Times.

Still, the canisters obtained in Afghanistan did not indicate that the group had yet accomplished that goal, the report said. The canisters were in fact so crude _ made of thin metal but not lead or lead-lined _ that any courier transporting them would have been exposed to harmful levels of radiation had the containers actually held prized nuclear material.

The containers were not imprinted with yellow labels accepted worldwide as radiation warnings or even the more common markings for medical waste, either of which might have indicated that the contents were purchased or stolen from a weapons laboratory, nuclear reactor, military installation or hospital.

“One just had a skull and crossbones painted on it by hand,” a US defence department official told the NYT. “It was a very primitive container. The people carrying it would have been exposed to radiation.”

The search for weapons of mass destruction in Afghanistan provided evidence of how hard it is to acquire sufficient fissionable material for a small atomic weapon, or even enough radioactive material for a “dirty bomb” in which laboratory waste or civilian nuclear fuel rods would be wrapped around a conventional explosive and detonated, spreading poison and contamination.

Officials said this analysis helps explain a notable section in President Bush’s State of the Union address, in which he warned of terrorists joining forces with states possessing biological, chemical or nuclear weapons.

The alliance would be a logical one for terrorists who have found they are unable to purchase those weapons or their components on the black market.

“States like these, and their terrorist allies, constitute an axis of evil, arming to threaten the peace of the world,” Mr. Bush said before a joint session of Congress on Jan 29.

“By seeking weapons of mass destruction, these regimes pose a grave and growing danger. They could provide these arms to terrorists, giving them the means to match their hatred.”

Defence Secretary Donald H. Rumsfeld and George J. Tenet, the director of central intelligence, have routinely warned that any group able to hijack airliners and slam them into office buildings would use even deadlier means of destruction if they could.

In testimony before the Senate select committee on intelligence this month, Mr Tenet said Osama had declared that acquiring unconventional weapons was “a religious duty”.