The head of the UN atomic agency has rejected as "baseless" Iranian accusations that the watchdog has been infiltrated by "saboteurs and terrorists."
"If I give a response it is very simple: it is baseless," International Atomic Energy Agency chief Yukiya Amano said in an event in London, a transcript of which was provided to AFP on Thursday.
He said that he had not responded earlier because he had not wanted to "dignify" the comments made in a speech at IAEA headquarters in Vienna on September 17 by Iran's nuclear chief Fereydoon Abbasi Davani.
"Sometimes it is not useful to dignify these claims with official answers," the Japanese told the event on Wednesday organised by the Chatham House think-tank.
Last November the IAEA published a raft of what it called "credible information" indicating that Iran had carried out "activities relevant to the development of a nuclear explosive device."
"The IAEA has not said that Iran has nuclear weapons. What we have said is that there is extensive, credible and consistent information suggesting that Iran has engaged in activities related to their development. Iran has a case to answer," Amano said on Wednesday.
Tehran has rejected the claims as being based on forgeries provided by its enemies and denies working, or ever having worked, on developing nuclear weapons.
It says that its activities are for peaceful purposes but the IAEA, which conducts regular checks on Iran's nuclear facilities, says that because of a lack of cooperation it cannot be certain that this is the case.
Multiple UN Security Council resolutions have called on Iran to suspend the most sensitive parts of its nuclear work, in particular uranium enrichment.