Iranian nuclear experts have taken environmental samples from the military base at Parchin without United Nations inspectors being present, the spokesman for Iran's atomic energy agency was quoted as saying on Monday.
The procedure for taking the samples, which could shed light on whether Iran's nuclear program ever had a military dimension, has been under intense discussion since Tehran reached a nuclear deal with world powers in July.
Western diplomats told Reuters earlier this month inspectors from the International Atomic Energy Agency (IAEA), the United Nations nuclear watchdog, would observe samples being taken.
"Iranian experts took samples from specific locations in Parchin facilities this week without IAEA's inspectors being present," Behruz Kamalvandi was quoted as saying by state news agency IRNA.
"They followed regulations and standards and the samples were given to IAEA's experts," the Atomic Energy Organization of Iran (AEOI) spokesman added. He did not rule out IAEA inspectors being present for future samples being taken.
IAEA chief Yukiya Amano visited the site at Parchin on Sunday, the agency's first visit there in a decade. Iranian state media described the visit as ceremonial rather than an inspection.