By Francois Murphy
VIENNA (Reuters) - Environmental samples have been taken at a sensitive military site in Iran, the head of the U.N. nuclear watchdog said on Monday, citing "significant progress" in its investigation of Tehran's past activities.
Inspecting the Parchin military site is a crucial part of the International Atomic Energy Agency's investigation of whether Iran previously carried out work related to developing nuclear weapons. The IAEA has not visited Parchin in a decade.
The agency is due to provide an assessment of "possible military dimensions" of Iran's nuclear program by the end of the year. That report is vital to Iran's breakthrough deal with major powers, under which limits will be placed on Tehran's atomic activities in exchange for a lifting of sanctions.
IAEA Director-General Yukiya Amano said he and the head of the agency's Department of Safeguards, which carries out inspections, visited a building at the Parchin site on Sunday that the agency had previously only observed by satellite.
"Inside the building, we saw indications of recent renovation work," Amano said in a statement he read to reporters in Vienna, where his agency is based. "There was no equipment in the building."
The IAEA did not identify the building or its location within the sprawling complex at Parchin, where Western intelligence has suggested Tehran carried out tests relevant to nuclear bomb detonations more than a decade ago. Iran has dismissed the intelligence as "fabricated".
But in a report to its Board of Governors last month, the IAEA said activities it had observed at a location within Parchin since 2012 could undermine its ability to verify what activity occurred there. Amano repeated this on Monday.
Those observations include the apparent construction of a small extension to a building, as well as the presence of vehicles and what seemed to be building materials, it said.
The IAEA has come under criticism over a confidential agreement with Iran governing how inspections are conducted at Parchin. Critics of the big powers' deal with Iran have argued that the IAEA's approach limits its ability to investigate and gives Iran too much influence in the collection of samples.
Under that arrangement, the samples would be taken by Iranian technicians while IAEA experts present at Parchin would observe and oversee the process, Western diplomats told Reuters.
INTEGRITY
Amano said environmental samples had been taken before his visit to Parchin on Sunday. He did not explain exactly how the samples were taken, but he said "the Iranian side played a part in the sample-taking process by swiping samples".
The IAEA has said it has a legal obligation to keep details of the arrangement confidential, but insists it is technically sound and will ensure the samples are not compromised.
"The agency can confirm the integrity of the sampling process and the authenticity of the samples, which were taken at places of interest to the agency at the particular location in Parchin," Amano told reporters.
"Authentication by the agency of the samples was achieved through use of an established verification process. The process was carried out under our responsibility and monitoring." The samples have been brought back to Vienna for analysis, he added.
A spokesman for Iran's atomic energy agency, however, was quoted on Monday as saying that Iranian nuclear experts had taken environmental samples from Parchin without U.N. inspectors around.
"Iranian experts took samples from specific locations in Parchin facilities this week without IAEA inspectors being present," Behruz Kamalvandi of the Atomic Energy Organization of Iran told the state news agency IRNA.
"They followed regulations and standards and the samples were given to IAEA's experts," he added. He did not rule out IAEA inspectors being present for future samples being taken.