AP Exclusive: Drawing Focuses on Iran's Nuke Work An image said to come from inside an Iranian military site shows an explosives containment chamber of the type needed for nuclear arms-related tests that U.N. inspectors suspect Tehran has conducted at the site. Iran denies such testing and has neither confirmed nor denied the existence of such a chamber. The image was provided to The Associated Press by an official of a country tracking Iran's nuclear program who said the drawing proves the structure exists, despite Tehran's refusal to acknowledge it. The official said he could not discuss the drawing's origins beyond that it was based on information from a person who had seen the chamber at the Parchin military site, adding that going into detail would endanger the life of that informant. His country, a member of the International Atomic Energy Agency, is severely critical of Iran's assertions that its nuclear activities are peaceful and asserts they are a springboard for making atomic arms. A former senior IAEA official said he believes the drawing is accurate. Olli Heinonen, until last year the U.N. nuclear agency's deputy director general in charge of the Iran file, said it was "very similar" to a photo he recently saw that he believes to be the pressure chamber the IAEA suspects is at Parchin. He said even the colors of the drawing matched that of the photo. After months of being rebuffed, IAEA and Iranian officials meet starting Monday in Vienna, and the IAEA will renew its attempt to gain access to the chamber, allegedly hidden in a building. Any evidence that Iran is hiding such an explosives containment tank, and details on how it functions, is significant for IAEA investigations. Beyond IAEA hopes of progress, that two-day meeting is being closely watched by six powers trying to persuade Iran to make nuclear concessions aimed at reducing fears that it may want to develop atomic arms as a mood-setter for May 23 talks between the six and Tehran in Baghdad. Warnings by Israel that it may attack Iran's nuclear facilities eased after Iran and the six - the United States, Russia, China, Britain, France and Germany - met last month and agreed there was enough common will for the Baghdad round. But with the Jewish state saying it is determined to stop Iran before it develops the capacity to build nuclear weapons, failure at the Iraq talks could turn such threats into reality. The IAEA has been stonewalled by Iran for more than four years in attempts to probe what it says is intelligence from member states strongly suggesting that Iran secretly worked on developing nuclear weapons. It first mentioned the suspected existence of the chamber in a November report that described "a large explosives containment vessel" for experiments on triggering a nuclear explosion, adding that it had satellite images "consistent with this information." It did not detail what the images showed. But a senior diplomat familiar with the IAEA's investigation who has also seen the image provided to the AP said they revealed a cylinder similar to the image at Parchin. Subsequent photos showed a roof and walls going up around the cylinder that then hid the chamber from satellite surveillance.