VIENNA: The U.N. atomic agency has received new and significant intelligence over the past month that Iran has moved further toward the ability to build a nuclear weapon, diplomats tell the Associated Press.

They say the intelligence shows that Iran has advanced its work on calculating the destructive power of an atomic warhead through a series of computer models that it ran sometime within the past three years.

The diplomats say the information comes from Israel, the United States and at least two other Western countries. The time-frame is significant because if the International Atomic Energy Agency decides that the intelligence is credible, it would strengthen its concerns that Iran has continued weapons work into the recent past – and may be continuing to do so.

Because computer modeling work is normally accompanied by physical tests of the components that go into a nuclear weapons, it would also buttress IAEA fears outlined in detail in November that Tehran is advancing its weapons research on multiple fronts.

Any new evidence of Iranian research into nuclear weapons is likely to strengthen the hand of hawks in Israel who advocate a military strike on Iran. They argue that Tehran is deliberately stalemating international efforts at engagement while continuing its clandestine weapons work.

Iran denies any interest in nuclear weapons and says suspicions that it ever tried to develop them are based on fabricated U.S., Israeli and other intelligence. At the same time, it has blunted IAEA efforts to investigate such claims for more than five years.

It also has scoffed at Western allegations that it is enriching uranium to make the core of nuclear warheads, saying it seeks only to create reactor fuel. But it refuses to accept offers of such fuel from abroad and is now producing material that is easier to turn into weapons-grade uranium than its main, lower-enriched stockpile.

Although some of the new information was said to have been supplied by the United States, it appears to run counter to the stated U.S. position that Iran shut down wide-ranging secret research and development of the components of a nuclear weapons program in 2003. At the same time the U.S. fears that Iran continues to move toward the threshold of making such arms by enriching uranium.

Ali Asghar Soltanieh, Iran’s chief IAEA delegate, cut short a telephone request for comment, saying he could not talk because he was in a meeting. In Tehran, meanwhile, Foreign Ministry spokesman Rahmin Mehmanparast told reporters that Iran would start answering the agency’s “questions and concerns” only when “our rights and security issues” are recognized.

An IAEA spokeswoman said the agency would not comment. But four of six diplomats said a passage in the IAEA’s August Iran report saying “the agency has obtained more information which further corroborates” its suspicions alludes to the new intelligence.