According to the report, written by Seymour M. Hersh, the White House received the information but did not hand it to the CIA.

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The report also stated that in the past six months, Israel and the United States had been working together to support a Kurdish resistance group known as the Party for Free Life in Kurdistan.

The group had been conducting clandestine cross-border forays into Iran, Hersh said he was told by a government consultant with close ties to the Pentagon civilian leadership, as "part of an effort to explore alternative means of applying pressure on Iran."

The government consultant said that Israel was supplying the Kurdish group "equipment and training." The group had also been given "a list of targets inside Iran of interest to the US" An Israeli government spokesman denied that Israel was involved.

The Israeli intelligence presented a stark contrast to recent CIA estimates on Iran's nuclear program, which claimed that Teheran was far from attaining a nuclear bomb.

The New Yorker article seemed to suggest that there was a difference of opinion between the CIA, the White House and the Pentagon with regards to the progress of Iran's nuclear weapons program.

The CIA's opinion was based on technical information gathered form satellites and other high-tech devices that suggested, that high levels of radiation had not been detected.

However, the White House and the Pentagon dispute the CIA's findings. Pentagon officials urged that the Israeli intelligence to be given due consideration and said that data gathered by satellites and ground sensors was insufficient. He added that more emphasis should be given to information supplied by agents (human intelligence).

"We live in an era when national technical intelligence" - data from satellites and on-the-ground sensors - "will not get us what we need. HUMINT may not be hard evidence by that standard, but very often it's the best intelligence we can get," said a Pentagon consultant.

Reportedly, the White House was refusing to reveal to the CIA the source of the Israeli information, the location of the site of the experiments, or the number of tests that had been carried out.

"The problem is that no one can verify it," a former senior intelligence official told Hersh. "We don't know who the Israeli source is. The briefing says the Iranians are testing trigger mechanisms" - simulating a zero-yield nuclear explosion without any weapons-grade materials - "but there are no diagrams, no significant facts. Where is the test site? How often have they done it? How big is the warhead - a breadbox or a refrigerator? They don't have that."

And yet, he said, the report was being used by White House hawks within the administration to "prove the White House's theory that the Iranians are on track. And tests leave no radioactive track, which is why we can't find it."

Still, he said, "The agency is standing its ground."