The U.N. nuclear watchdog said on Tuesday information stolen from one of its former servers had been posted on a hacker website and it was taking "all possible steps" to ensure its computer systems and data were protected.

The stolen information was contained in a statement by a group with an Iranian-sounding name calling for an inquiry into Israel's nuclear activities. The International Atomic Energy Agency (IAEA) is investigating Iran's nuclear program.

The IAEA said the theft concerned "some contact details related to experts working" with the Vienna-based agency but it did not say who might have been behind the action.