For close to a year, diplomats say, a report on Iran's alleged nuclear weapons experiments has been sitting in a drawer of a UN nuclear monitoring agency, with access limited to only a few top officials.
The question is whether the document – a summary of all the International Atomic Energy Agency knows about Iran's nuclear program – will be made public when agency publishes its latest report on Iran within two weeks.
As that date approaches IAEA chief Mohamed ElBaradei is faced with the tough choice of sharing all his agency findings about Iran's alleged arms programs, or leaving the decision to his successor later this year.
The existence of a secret IAEA summary of Iran's alleged weapons experiments based on agency investigations and US and other intelligence was confirmed to The Associated Press over the past few days by three senior western diplomats from nations accredited to the IAEA, as well as a senior international official who follows the Iran nuclear issue.
What's more, the information concerning allegations that Iran actively pursued research into developing nuclear warheads and the way to deliver them has been available since September, the diplomats say.
Since then, the US and its allies have pushed the agency to circulate the summary among the IAEA's 35 board member nations of what it knew and its conclusions about the allegations, said the diplomats, who demanded anonymity for discussing confidential issues.
But although even some of his senior aides favor publication, ElBaradei has balked, they said. The agency chief has been keen to avoid moves that could harden already massive Iranian intransigence on cooperating with his agency on probing the allegations and on other issues - and of pushing the US or Israel closer to a possible military strike on Tehran's nuclear facilities.
IAEA spokesman Marc Vidricaire said Thursday the agency would not comment.
The Nobel Peace Prize-winning IAEA chief may possibly already be focusing on his legacy as his 12-year tenure winds down.
A restricted draft resolution shared with the AP and prepared by his agency for a 35-nation board meeting starting September 7 pays "tribute" to Elbaradei and lauds the "significant contribution" he has made to the work of the agency and "the cause of international peace and security during his distinguished and successful tenure as Director General."
The draft calls for him to be named "Director General Emeritus" – an honor also accorded to his immediate predecessors.
His last day is November 30. And as that date draws closer ElBaradei has repeated calls for talks on and with Iran instead of tough talk – gaining praise from the developing world but enforcing the view among his Western critics that he often oversteps his agency's mandate as purely technical organization with no political message.
He also has sharp words for his critics: "As to how we write our reports, that's our business," he told a June session of the board.
Washington unsuccessfully lobbied in 2005 to block ElBaradei's reappointment because his statements on Iraq and Iran were peppered with barely disguised criticisms of US policy. The West has also viewed some statements on Israel and Gaza as overtly political, even while they were praised by Arab nations and their backers.
Elbaradei's reports on Iran have become more critical after months of continued Iranian stonewalling of IAEA efforts to monitor and investigate Iran's nuclear programs.
Still, Western delegations say they do not go far enough in faulting Tehran for withholding information and continuing to expand uranium enrichment, which can create both nuclear fuel and the fissile material for warheads.
Iran dismisses the weapons programs allegations as groundless and ElBaradei himself has said there is no "concrete evidence" that Iran was engaged in such work - even while suggesting two months ago that Tehran wants to have the capability to build such arms.
But a senior diplomat who regularly talks with leading agency experts told the AP last year that the experts viewed much of the intelligence forwarded by the US and other nations on alleged secret Iranian nuclear arms work as "compelling."
US intelligence includes material on a laptop computer reportedly smuggled out of Iran and indicating that Tehran had been working on details of nuclear weapons, including missile trajectories and ideal altitudes for exploding warheads.
Mock-ups of missile re-entry vehicle
Among other intelligence Washington also gave the agency information on the alleged "Green Salt Project" – a plan the US claims links diverse components of a nuclear weapons program, including uranium enrichment, high explosives testing and a missile re-entry vehicle, with diagrams in Iran's possession showing how to mold uranium metal into warhead form.
Diplomats attending closed-door IAEA presentations to board member nations have said they were shown an Iranian video depicting mock-ups of a missile re-entry vehicle that the presenter suggested seemed designed to carry a nuclear warhead.
Ahead of the next ElBaradei Iran report, one of officials interviewed for this article suggested ElBaradei was likely to heed the pressure and focus in some way on what the agency knows or surmises on Iran's alleged weapons programs.
But he declined to say what the information was, whether it would be complete and if it would be in annex form or in a report subsection.
Until recently, ElBaradei appeared to be facing another thorny issue in the upcoming report – how toughly to take Iran to task for stonewalling IAEA requests to expand its monitoring of its Natanz uranium enrichment site.
But that issue appeared defused with diplomats telling The AP Thursday that Iran last week agreed to meet at least some of the requests. The agency had been seeking additional cameras and inspections of the Natanz site, to keep track with the rapidly expanding enrichment program which – if modified – can make the fissile core of warheads.
Iran's stonewalling had raised agency concerns that its experts might not be able to make sure that some of the enriched material produced at Natanz is not diverted for potential weapons use.
In addition, the diplomats said, Iran allowed IAEA experts last week to visit its heavy water reactor site near Arak in central Iran, lifting a yearlong ban that the agency said contravened mutual agreements.
Western countries have repeatedly called on Iran to stop construction of the reactor, fearing it could be used as a second track toward building a warhead - when finished, say experts, it could produce enough plutonium for a nuclear weapon each year.
But there is no compromise in sight on the issue of allegations Iran worked on developing nuclear arms.
Iran insists it never did – and has blocked IAEA attempts to probe the issue. But the West says Tehran is hiding such past experiments. So the question of whether to go public with what the IAEA knows has become a subject of debate among key IAEA members – and within the agency itself.