Traces of bomb-grade uranium found two years ago in Iran came from contaminated Pakistani equipment and are not evidence of a clandestine nuclear weapons programme, a group of US government experts and other international scientists has determined.‘‘The biggest smoking gun that everyone was waving is now eliminated with these conclusions,’’ said a senior official who discussed the still-confidential findings on the condition of anonymity. Scientists from the United States, France, Japan, Britain and Russia met in secret during the past nine months to pore over data collected by inspectors from the International Atomic Energy Agency, according to US and foreign officials. Recently, the group, whose existence had not been previously reported, definitively matched samples of the highly enriched uranium—a key ingredient for a nuclear weapon—with centrifuge equipment turned over by the government of Pakistan. Iran has long contended that the uranium traces were the result of contaminated equipment bought years ago from Pakistan. But the Bush administration had pointed to the material as evidence that Iran was making bomb-grade ingredients. The conclusions will be shared with IAEA board members in a report due out the first week in September, according to US and European officials who agreed to discuss details of the investigation on the condition of anonymity.The report ‘‘will say the contamination issue is resolved,’’ a Western diplomat said. US officials have privately acknowledged for months that they were losing confidence that the uranium traces would turn out to be evidence of a nuclear weapons programme. US officials, eager to move the Iran issue to the UN Security Council, which has the authority to impose sanctions, have begun a new round of briefings for allies designed to convince them that Iran’s real intention is to use its energy programme as a cover for bomb building. The briefings will focus on the White House’s belief that a country with as much oil as Iran would not need an energy programme on the scale it is planning, according to two officials. —LAT-WPIran N-talks offPARIS: European powers have called off the August 31 talks with Iran over its nuclear programme, France said on Tuesday, marking a breakdown in two years of negotiations with Tehran to halt its sensitive atomic work. French Foreign Ministry spokesman Jean-Baptiste Mattei said talks on a formal European proposal made earlier this month would not now go ahead because Iran had resumed certain nuclear work in breach of a promise to freeze it while talks lasted. REUTERS
