Senior diplomats close to the Vienna-based International Atomic Energy Agency said the IAEA was not getting the cooperation it needs in investigating Iran's atomic activities, despite the Islamic Republic's repeated promises to provide access for full and transparent reporting.

Non-proliferation expert Gary Samore told AFP from the International Institute for Strategic Studies think tank in London that Iran's "level of cooperation with the IAEA has really deteriorated over the past few months."

"My understanding is that the Iranians have destroyed some facilities and razed them to the ground. The suspicion is that these facilities were involved in nuclear development," he said.

A diplomat close to the IAEA said that while the Iranian nuclear industry "rips down buildings" as part of its work, the Iranians "have not ripped down something the IAEA has inspected." He refused to say if this were true about sites the IAEA wanted now, or in the future, to inspect.

The Iranians had re-painted a workshop and done some construction work at a workshop at the Kalaye Electric Company in Tehran in which the IAEA was interested.

Despite this, IAEA inspectors last year found contamination at the site by highly enriched uranium particles.

At stake is what the IAEA's 35-nation board of governors will decide when it meets at the agency's headquarters in Vienna on June 14.

The United States claims Iran is hiding a program to build the bomb and has called for the IAEA, which has been investigating the Iranian program since February 2003, to refer the Islamic Republic to the UN Security Council for possible international sanctions.

But diplomats said the IAEA will be unable to make a final finding on Iran due both to Tehran's delaying international inspections and because an Iranian declaration on its nuclear program filed last week came too late to be fully evaluated before June 14.

The military sites in question are seven workshops for manufacturing centrifuge components which are owned by military industrial organizations at three locations.

Centrifuges are used to enrich uranium. Highly enriched uranium can be used to make an atomic bomb.

The IAEA visited the workshops at the military sites last January and can return, but Iran has only been willing to give "managed access," according to an IAEA report in February.

The IAEA said in a "note" it wrote in March that "the agency's visit was 'managed' in the sense that inspectors were not permitted to take pictures with IAEA cameras or use their own electronic equipment."

The IAEA "wants to agree on certain arrangements so the inspectors can do their jobs," a diplomat, who asked not to be named, said.

The diplomat said the IAEA inspectors were guided on their last visit by Revolutionary Guard soldiers.

The inspectors need to be able to move freely and to use their own equipment, the diplomat said.

He said the inspectors should be visiting the military sites soon as there appeared to be an agreement for the inspectors to go "without compromising the basic IAEA mission."

Iranian ambassador to the IAEA Pirooz Hosseini said there was no problem with managed access.

"A military site is not a shopping center. It is an important place for any country," he said.

He said the IAEA inspectors were "guided by some escorts and taken to the place they want to see. In the field, cooperation is going on very well."

But another diplomat pointed to this problem of unfettered access as a sign "the Iranians give cooperation reluctantly and only after being persuaded to do so."

Samore said there are suspicions that the Iranian Revolutionary Guards have been hiding "a parallel program to work on centrifuges and nuclear weapons designs as well."

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