Iran on Saturday said it wanted to first see Western intelligence reports before allowing the International Atomic Energy Agency (IAEA) to inspect the Parchin military complex in south east of the capital Tehran, dpa reported.
The UN nuclear watchdog wants to inspect Parchin, where alleged tests on nuclear warheads have been conducted according to such confidential reports.
While denying the accusation, Iran says the Parchin complex is not registered as nuclear site and the IAEA is therefore not authorized to inspect the complex.
"One of the reasons we have not come to any agreement with the IAEA yet is that we insist on first seeing the (intelligence) documents which contain the accusations and claims by some Western countries," Iran's IAEA Ali-Asqar Soltanieh told ISNA news agency.
"This is a very logical demand and after that we can discuss the modalities and come to a logical conclusion," the Iranian envoy said.
Teheran has, however, not fully denied all access.
"It is quite obvious that any agreement with the IAEA (on Parchin) should be made on the basis of clear criteria but normal IAEA inspections of all our nuclear sites are continuing as before," Soltanieh said.
Iranian Foreign Minister Ali-Akbar Salehi on Friday rejected as baseless a report by the IAEA that accused it of covering up the alleged tests at Parchin.
Salehi said that such charges had no technical basis, and were politically motivated, adding that anybody with sufficient technical knowledge was aware that no one could clean any venue from traces of nuclear tests.
Western powers suspect Iran wants to make a nuclear bomb. Iran denies this and says its disputed nuclear programme is peaceful.