The UN nuclear watchdog has said its independence is paramount and it does not take intelligence presented to it at face value, in an apparent response to Prime Minister Benjamin Netanyahu's description of a "secret atomic warehouse" in Iran.

"The agency sends inspectors to sites and locations only when needed. The agency uses all safeguards relevant to information available to it but it does not take any information at face value," International Atomic Energy Agency chief Yukiya Amano said in a statement on Tuesday.

"In order to maintain credibility, the agency's independence in relation to the implementation of verification activities is of paramount importance," he said.

"All information obtained, including from third parties, is subject to rigorous review and assessed together with other available information."

Netanyahu made the revelation during his address at the UN General Assembly last week and called on the IAEA to inspect the facility immediately.

Open gallery view The location of the site in Tehran Netanyahu reveled during his UN address. Credit: Google Maps

He said the Iranian facility contains technology for Iran's nuclear program, adding that Iran "took this radioactive material and spread it around Tehran like Nutella." According to Netanyahu, Iran removed 15 kilograms of radioactive material from the warehouse last month, and that it contained up to 300 tons of nuclear-related material.

"I have a message for tyrants of Tehran – Israel knows what you're doing," Netanyahu said. He added that Israel will continue to act against Iran – "also in Syria and also in Iraq."