(Reuters) - The U.N. nuclear watchdog showed new satellite imagery on Wednesday indicating that Iran may be cleaning a site where inspectors suspect it has carried out tests relevant to developing atomic bombs, participants at a closed-door briefing said.

One person who attended the presentation by senior U.N. nuclear agency officials for diplomats accredited to the International Atomic Energy Agency said a May 25 image showed ground scraping activities at the Parchin military site.

Another envoy said one building also appeared to have been removed from the site, compared with earlier images of the same place.

Last week, the IAEA said in a report issued to member states that satellite images showed extensive activities at the facility southeast of Tehran.

It did not elaborate, but Western diplomats say they suspect Iran is trying to remove any incriminating evidence from the site, which the U.N. agency wants to visit as part of its probe into possible military dimensions to Iran's nuclear program.

Iran, which denies Western accusations it is seeking to develop nuclear weapons capability, has dismissed charges aired about Parchin as childish and ridiculous.