Updated at 11:58 p.m.
The U.N. atomic agency expressed alarm Monday about Iran's decision to bar some of its inspectors, suggesting that its efforts to monitor the country's nuclear program were suffering as a result.
The unusually blunt International Atomic Energy Agency warning was voiced in a restricted report on Iran made available to The Associated Press that otherwise contained few surprises. It followed Iran's recent decision to strip two experienced inspectors of the right to monitor its nuclear activities after the two reported what they said were undeclared nuclear experiments.
The Islamic Republic says the reporting by the two was inaccurate, but the IAEA stands by the findings. And the 11-page IAEA document issued Monday devoted a special section to the complaint, reflecting the importance attached to it by IAEA chief Yukiya Amano.
Such a section was included in only one previous report, after Iran stripped the right of dozens of inspectors in 2006 and 2007 - most of them in order to show displeasure over recently passed U.N. Security Council sanctions on the Islamic Republic.
Monday's report said that objections by Iran to some experienced inspectors "hampers the inspection process and thereby detracts from the Agency's capability to implement effective and efficient safeguards in Iran."
Diplomats from three countries accredited to the agency echoed the IAEA's concerns in comments to the AP, saying Iran appeared keen to ban seasoned inspectors - particularly those from nuclear weapons countries with special skills that could help detect attempts to make nuclear arms.
And a U.N. official who was a former IAEA inspector in Iran spoke of intense scrutiny while on such missions and the fear among inspectors that they would be banned from returning if they reported something the Iranians did not like.
"If you opened your eyes too much you ran the risk of being de-designated" by the Iranians said the official who - like the diplomats - asked for anonymity because his information was confidential.
He said he agreed with the concerns that Iran was weeding out experts most likely to discover secret programs designed to make weapons.
"The IAEA doesn't teach you about weaponization," he said. "Only experts from weapons countries are good at that kind of thing."
Iran rejected allegations of selective bans and intimidation of IAEA inspectors, with Ali Asghar Soltanieh, Tehran's chief delegate to the agency calling them "absolutely unjustified."
Soltanieh told the AP that the IAEA currently has 150 inspectors able to work in Iran and noted that the report mentioned the country's approval of five additional inspectors.
That, he said, "is a clear indication that we have cooperated with the agency."
The quarterly report, which was being circulated to the IAEA's 35-nation board and to the U.N. Security Council, also confirmed public statements by Iranian officials that the country continues to enrich uranium in contravention of U.N. Security Council demands.
Iran insists it only wants to enrich uranium to create energy. But international concerns are high because enrichment can also create the fissile core of nuclear warheads - low enriched uranium is used as nuclear fuel but the same process can produce high enriched, weapons-grade material.
The report noted that while the scope of enrichment had not significantly increased over the past year, output had been steady, with Iran now accumulating about 2.8 tons of low-enriched material - nearly enough for three nuclear bombs - since its program was revealed seven years ago. That translates to about 15 percent more such material than in May, when the last IAEA report was published.
Separate enrichment for what Iran says will be fuel for its research reactor had produced about 22 kilograms - more than 45 pounds - of 20-percent enriched uranium.
While still substantially less than the 90 percent needed to make weapons, production of 20 percent enriched material is of concern because it can be turned into weapons grade material more quickly than the low enriched uranium turned out by Iran's main enrichment facility.
The report also said that Iran continued to stonewall the agency in its efforts to follow up on U.S. and other intelligence indicating past experiments meant to develop a nuclear weapons program and warned that chances of establishing the accuracy of such information were diminishing.
With Iran refusing to engage on the issue for over two years, "the possible deterioration in the availability of some relevant information increase the urgency of this matter," said the report.
In a separate report, the agency expressed similar concerns about Syria's refusal allow the IAEA to probe U.S. assertions that a facility destroyed three years ago by Israeli warplanes was a secretly built reactor meant to produce plutonium.
"After two years of investigations constrained by Syria's lack of cooperation, it is critical that Syria positively engage with the Agency ... without further delay," said that report.