Intelligence provided to the United Nations' nuclear watchdog agency shows that Iran has mastered the critical steps needed to build a nuclear weapon, The Washington Post reported on Sunday.
According to the intelligence, Iran appears to have received crucial technical assistance from foreign experts, the newspaper reported, citing Western diplomats and nuclear experts briefed on the findings by the International Atomic Energy Agency (IAEA).
The IAEA report, to be issued this week, is expected to be its most detailed yet on research in Iran seen as geared to developing atomic bombs and is expected to spur Western powers to press for more sanctions on Iran.
The Washington Post said the report's findings provide new details on the role played by a former Soviet weapons scientist who allegedly tutored Iranians on high-precision detonators of the kind used to trigger a nuclear chain reaction.
The report says the intelligence also supports concerns that Iran continued to conduct weapons-related nuclear research after 2003, when US intelligence agencies believed Iran halted the research in response to international pressure.
Western powers believe Iran is trying to develop nuclear weapons under cover of a civilian nuclear energy program. Tehran denies wanting atom bombs, saying it is enriching uranium only to power reactors for electricity generation.
The United States, the European Union and their allies have imposed economic sanctions on Tehran for refusing to halt its uranium enrichment program. The United States and Israel have repeatedly hinted at the possible use of force against Iranian nuclear sites, eliciting threats of fierce retaliation from the Islamic Republic.
New disclosures in the IAEA report provide details on an apparent secret research program that was more ambitious, more organized and more successful than commonly suspected, The Washington Post said.
The Post quoted David Albright, a former IAEA official who reviewed the agency's findings, as saying that based on the intelligence the UN agency has concluded that Iran "has sufficient information to design and produce a workable implosion nuclear device" using highly enriched uranium as its fissile core.
Albright described some of the highlights at a private conference of intelligence professionals last week, the newspaper said, adding that it had obtained slides from the presentation and a summary of Albright's notes.