The UN agency believes Iran may have conducted explosives tests that could help develop nuclear weapons at Parchin and wants immediate access to investigate the facility. Iran denies this, saying Parchin is a conventional military complex.

The latest satellite image, dated November 7, showed what appeared to be piles of dirt, according to diplomats who attended the briefing by chief UN inspector Herman Nackaerts.

“They have been scraping the earth. Now they obviously want to put down new earth. There are piles of them that you can see,” one diplomat said, adding a fence had also come down.