In 2003 Iran agreed to let officials from the International Atomic Energy Agency into the country to look at its nuclear facilities. Olli Heinonen was one of the inspectors tasked with trying to establish whether or not Iran was trying to develop nuclear weapons. He's been speaking to Tim Mansel about what they found. Photo:The Iranian nuclear power plant of Natanz, south of Tehran.(Credit:Henghameh Fahimi/AFP/Getty Images)