VIENNA, Dec 2: Inspectors from the UN nuclear watchdog would like to visit a military complex in Iran that an exile group said housed a nuclear weapons site, but they lack the legal authority to go there, UN diplomats said.

Iran, which insists its nuclear programme is solely for electricity generation, earlier this week escaped possible UN Security Council economic sanctions after agreeing to freeze all activities that could be used to make bomb-grade material. But several military sites inspectors would like to inspect are legally off-limits to the International Atomic Energy Agency (IAEA), which only has clear rights to visit facilities declared to it as nuclear sites. Access to other facilities must be negotiated and can be highly problematic.

"The IAEA simply has no authority to go to sites that are not declared nuclear sites," a diplomat close to the IAEA inspection process said. He said the agency needed Iran's permission to inspect undeclared sites. The IAEA had not asked to inspect Lavizan II, although it would like to.

Spokesman Mark Gwozdecky declined to comment. "We are not commenting ... as we do not conduct the inspections process through the media," he said. Last December, Iran signed the IAEA's Additional Protocol, granting the agency more authority to conduct short-notice, intrusive inspections, but only to declared sites.

Although the protocol has not been ratified, Tehran has been acting as if it was in force. IAEA chief Mohamed ElBaradei has asked Iran many times for access to Parchin, but a November report by the IAEA said it had received no response from Tehran.

"DEPRESSING": One UN diplomat described it as "depressing" that the National Council of Resistance of Iran (NCRI), an Iranian exile Group, said recently that Lavizan II was a secret atomic weapons site and then days later reported it was being stripped clean.