The independent Arman daily quoted Asghar Zarean, deputy head of Iran's nuclear department, as saying that Iranian nuclear experts thwarted the sabotage attempt "in recent weeks" but did not provide a more specific timing.
"Thanks to the full alertness of our colleagues, we were able to detect and defuse the sabotage attempt," said Zarean, who is also in charge of security at Iran's nuclear agency.
An unidentified foreign country was behind the attempt, Zarean added without elaborating. He did not indicate what kind of result the sabotage meant to achieve.
Tehran has long accused the West of working to sabotage its nuclear program, which the international community suspects is geared for nuclear arms manufacturing. Iran denies the charges, saying the program is meant for peaceful purposes such as power generation and medical research.
In 2010, the so-called Stuxnet computer virus temporarily disrupted the operation of thousands of centrifuges used in nuclear fuel production at Iran's uranium enrichment facility in the central city of Natanz.
"The enemy should know that it cannot take any action against Iran's nuclear activities. In fact, Iran is able to find and defuse any sabotage in both hardware and software fields," said Zarean.
In September, authorities arrested a Ukrainian national suspected of sabotage at the Bushehr nuclear power plant. At the time, Iran's Hamshahri daily said the "Ukrainian expert" was affiliated with a Russian contractor that works at Bushehr, which went online in 2011 with Russian aid.
