Previously undisclosed information contained in the annex, said the diplomats, will include:

– Intelligence from unnamed member states that a bus-sized steel container, located at the Iranian military base of Parchin is likely being used for nuclear-related high explosives testing of the kind needed to release an atomic blast. The agency has satellite imagery of the container.

– Expanded evidence that Iranian engineers worked on computer models of nuclear payloads for missiles.

Significantly, said the diplomats, these alleged experiments took place after 2003 – the year that Iran was believed to have stopped secret work on nuclear weapons, according to a 2007 U.S. intelligence assessment. But diplomats have told the AP that Tehran continued arms-related experiments in a less concentrated way after that date, a view reflected by recent IAEA reports that have detailed suspicions that such work may be continuing up to the present.