DUBAI - Reports that Iran's Parchin military facility may have been cleaned before a visit by the International Atomic Energy Agency (IAEA) are "invalid propaganda," Iran's Foreign Ministry said on Tuesday.IAEA inspectors were refused access to the site in Tehran in February. But last week Iran's diplomatic mission to the UN's nuclear watchdog said it would allow inspectors to visit the site one more time.An IAEA report last November contended that Iran had constructed a large containment chamber at Parchin to conduct explosives tests which it described as strong indicators of efforts to develop nuclear weapons.Suspicions that the site might be used for atomic research and experiments date back to 2004 following assessments of satellite images.Iran has repeatedly rejected Western accusations that its nuclear progam is a cover for developing nuclear weapons, saying its goals are peaceful.The P+1 group of countries has accepted an offer made by Tehran for further negotiations on its nuclear program, the details of which, Mehmanparast said, are expected to be confirmed soon.The Foreign Ministry spokesman reasserted Iran's right to pursue peaceful nuclear technology under the Nuclear Non-Proliferation Treaty and condemned the actions of what he called the "Zionist regime" in assassinating Iranian nuclear scientists.At least four scientists associated with Iran's nuclear program have been assassinated since 2010 and a fifth was wounded in a bomb attack.Israeli officials do not comment on whether they are behind the killings. Israel has threatened last-ditch military action to prevent Iran possessing nuclear weapons.Western diplomats say Iran may be postponing any visit to the site to give it time to sanitize the facility of any incriminating evidence of explosives tests that would indicate efforts to design nuclear weapons. Last week, the IAEA chief Yukiya Amano told Reuters he did not rule out the possibility."Parchin is a military site where conventional military activities take place. Comments about cleaning up military nuclear tests are not accurate or wise. This is invalid propaganda," said the Foreign Ministry spokesman, Ramin Mehmanparast, during a televised weekly news conference."Those who are familiar with technical issues know that such comments are not important. If nuclear test activities take place at a site, the evidence cannot be hidden."Referring to the last visit of IAEA inspectors, Mehmanparast said: "If the agency's team had had more patience and could have stayed longer, maybe they could have made the visit after an agreement was reached on the framework."