NEW YORK, March 12: The International Atomic Energy Agency (IAEA) is seeking Islamabad's permission to acquire environmental samples from the Pakistani uranium enrichment facilities to see if they match the weapons-grade traces its inspectors found in Iran , the New York Times reported on Thursday.

The IAEA officials told the paper that the contamination might have originated in Pakistan. It was pointed out that Dr Abdul Qadeer Khan had admitted secretly supplying uranium enrichment equipment to Iran and other nations.

"Pakistan could let Iran off the IAEA hook," the newspaper quoted a European diplomat in Vienna as saying.

Quoting unnamed American and European diplomats, the newspaper said some of the traces UN inspectors detected last year were refined to 90 per cent of the rare 235 isotope - the purity reserved for use in a nuclear bomb.

While the IAEA previously reported finding "weapons-grade" traces, it has not revealed that some reached such a high degree of enrichment, the Times said.

The presence of such traces raises the stakes in the international debate over Iran's nuclear programme and increases the urgency of determining the uranium's origin, the report said. "If the enrichment took place in Iran, it means the country is much further along the road to becoming a nuclear weapons power than even the most aggressive intelligence estimates anticipated," it said.

Iran maintained that its nuclear programme was for purely peaceful purposes, while the US contended it had secretly tried to produce nuclear weapons. Iran has denied that its programme is weapon-oriented.

Iran maintains that all of the highly enriched uranium found on its nuclear facilities was contamination that occurred before imported equipment arrived in the country. Iranian officials said they could not identify the origin of the contamination because the equipment was imported through middlemen in five countries.