The International Atomic Energy Agency (IAEA) said on Monday that a refusal by Syria to allow UN inspectors access to a site where secret nuclear activity may have taken place is endangering potential evidence in the investigation, according to a Reuters report.

In a confidential report obtained by Reuters, the IAEA said that it has not been allowed to inspect the site for two years.

"With time, some of the necessary information may deteriorate or be lost entirely," wrote IAEA chief Yukiya Amano in the report.

The site in question is the same site bombed by Israeli Air Forces exactly three years ago, in September of 2007. The CIA confirmed that the site, known as al-Kibar or Dair Alzour, was a nuclear facility meant to produce plutonium and partially funded by North Korea. Israel bombed the reactor before it attained its planned capacity to manufacture plutonium for nuclear weapons.

The IAEA has already said earlier this year that some illicit atomic activity had taken place at the site, when it reported that inspectors found uranium traces during a 2008 visit to the site. IAEA now wishes to re-examine the site and take samples from rubble removed immediately after the air strike.

In the report, Amano urges Syria to cooperate in respect to Dair Alzour, and also calls on Syria to allow the IAEA access to three other Syrian sites under military control whose appearance was altered by landscaping after inspectors requested access to them.

Earlier on Monday, the IAEA reported that Iran continues to snub the United Nations and has produced 2.8 tons of enriched uranium, and added that the Islamic Republic refuses to allow UN inspectors into the country, noting it recently took away the rights of two experienced inspectors to monitor Iran’s nuclear projects after they reported that Iran conducted undeclared nuclear experiments. Iran claims it barred entry to the inspectors because their reports were not accurate.