Iran on Sunday denied it had received nuclear technology from Pakistan's top nuclear scientist, who admitted to having passed secrets to the Islamic republic.
Foreign ministry spokesman Hamid Reza Asefi said Tehran had bought pieces of equipment that could raise suspicions and subsequently turned over the sellers' names to the UN's International Atomic Energy Agency (IAEA).
"Pakistan's worries are Iran's worries, but what is being raised in the media is not true," Asefi said, according to the state news agency IRNA, in the government's first reaction to the confession by Abdul Qadeer Khan.
Khan on Wednesday admitted leaking nuclear secrets to Iran, Libya and North Korea for personal profit following an investigation based on information from the IAEA.
"The Islamic Republic has bought certain parts from the middlemen whose names have been reported to the International Atomic Energy Agency," Asefi said, although he made no mention of having received atomic know-how, such as blueprints which were made available through Khan on the black market.
"It is evident that the Islamic Republic is not aware of what is going on behind the scenes and we have just reported to the International Atomic Energy Agency the names of the middlemen from whom we bought the parts," he said.
"Pakistan is among the Islamic Republic's friends and we attach enormous importance to ties with Pakistan," he said.
Iran has been asked by the IAEA to come clean on its nuclear programme, after hiding sensitive aspects, including enriching small amounts of uranium and plutonium, for 18 years.
It has defended its "inalienable right" to use nuclear energy for peaceful ends, although the United States suspects it is hiding a weapons programme.
Pakistan's Foreign Minister Khurshid Mahmud Kasuri defended on Sunday its decision to pardon Dr Abdul Qadeer Khan at the centre of a nuclear probe and said he was only one of many in the world spreading atomic know-how, mainly to Iran.