The Acting Director General of the International Atomic Energy (IAEA), Cornel Feruta, "today informed the IAEA Board of Governors that an Agency inspector was last week temporarily prevented from leaving Iran," a statement from the agency said.

According to the statement, Feruta said: "Preventing an inspector from leaving a country, particularly when instructed to do so by the Agency, is not acceptable and should not occur."

Iran said Thursday it had cancelled the inspector's accreditation after she triggered an alarm last week at the entrance to the Natanz uranium enrichment plant.

In its statement the IAEA said that it could not go into details "but based on the information available to us, the Agency does not agree with Iran's characterisation of the situation involving the inspector, who was carrying out official safeguards duties in Iran".

"The Agency will continue to consult with Iran with a view to clarifying the situation," the statement said.

Earlier on Thursday Iran's Ambassador to the IAEA Kazem Gharib Abadi denied the inspector was ever detained, saying she was allowed to leave the country despite ongoing investigations into last week's incident.