I seriously doubt that they've found the evidence that would support whatever they're alleging. They haven't so far.
Here's the report I read this morning which cites 'fears' but mostly just circumstantial evidence beyond Iran's statements about further enrichment:
Iranian nuclear activities suggest that it has conducted work aimed at preparing a nuclear warhead that could be placed on a missile, International Atomic Energy Agency chief Yukiya Amano said today in a report to the agency's 35-nation governing board
"The information available to the agency ... is extensive and has been collected from a variety of sources over time. It is also broadly consistent and credible in terms of the technical detail, the time frame in which the activities were conducted and the people and organizations involved," the new director general stated.
"Altogether, this raises concerns about the possible existence in Iran of past or current undisclosed activities related to the development of a nuclear payload for a missile. These alleged activities consist of a number of projects and sub-projects, covering nuclear and missile related aspects, run by military related organizations."The U.S. intelligence community said in 2007 that it believed that Tehran had ended nuclear-weapon operations several years earlier. That conclusion, though, has been met with skepticism in Washington and other allied nations.
"Since August 2008, Iran has declined to discuss" the agency's inquiries regarding nuclear-weapon design activities allegedly carried out by the nation, the IAEA report says.
"With the passage of time and the possible deterioration in the availability of information, it is important that Iran engage with the agency on these issues, and that the agency be permitted to visit
all relevant sites, have access to all relevant equipment and documentation, and be allowed to interview relevant persons, without further delay," Amano wrote.
link:
http://www.globalsecuritynewswire.org/gsn/nw_20100218_7848.phpthat's far short of proof, imo.