VIENNA -- Iran will be allowed to use its own inspectors to investigate a site it has been accused of using to develop nuclear arms, operating under a secret agreement with the UN agency that normally carries out such work, according to a document seen by The Associated Press.

The revelation yesterday newly riled Republican lawmakers in the United States who have been severely critical of a broader agreement to limit Iran's future nuclear programs, signed by the Obama administration, Iran and five world powers last month.

Those critics have complained that the wider deal is unwisely built on trust of the Iranians, while the administration has insisted it depends on reliable inspections.

A skeptical House Speaker John Boehner (R-Ohio) said, "President Obama boasts his deal includes 'unprecedented verification.' He claims it's not built on trust. But the administration's briefings on these side deals have been totally insufficient -- and it still isn't clear whether anyone at the White House has seen the final documents."

The newly disclosed side agreement, for an investigation of the Parchin nuclear site by the UN's International Atomic Energy Agency, is linked to persistent allegations that Iran has worked on atomic weapons.

That investigation is part of the overarching nuclear-limits deal.

Evidence of the inspections concession is sure to increase pressure from U.S. congressional opponents before a Senate vote of disapproval on the overall agreement in early September.

The Parchin agreement was worked out between the IAEA and Iran. The United States and the five other world powers were not party to it but were briefed by the IAEA and endorsed it as part of the larger package.

White House National Security Council spokesman Ned Price said yesterday the Obama administration was "confident in the agency's technical plans for investigating the possible military dimensions of Iran's former program . . . The IAEA has separately developed the most robust inspection regime ever peacefully negotiated."

All IAEA member countries must give the agency some insight into their nuclear programs. The agreement in question diverges from normal procedures by allowing Tehran to employ its own experts and equipment in the search for evidence of activities it has consistently denied -- trying to develop nuclear weapons.

advertisement | advertise on newsday

While the document says the IAEA "will ensure the technical authenticity" of Iran's inspection, it does not say how.

Iranian diplomats in Vienna were unavailable for comment yesterday while IAEA spokesman Serge Gas said the agency had no immediate comment.