WASHINGTON: The inquiry into a militant attack on a US mission in Libya has been completed and the Secretary of State, Hillary Clinton, is reviewing it, a senior official said.
The findings of the Accountability Review Board set up by Mrs Clinton after the September 11 attack on the US consulate in Benghazi could unleash a Christmas bombshell for the US administration.
Four Americans, including the ambassador, Chris Stevens, died in the assault by heavily armed militants who overran the consulate then unleashed a hail of mortar fire on a nearby annex being used as a safe house.
Republicans have criticised the administration for failing to provide proper security and for allegedly trying to cover up the attackers' ties to al-Qaeda.
The report included an unclassified part and a separate classified section which would not be released to the public, a State Department spokeswoman Victoria Nuland said.
Mrs Clinton was forced to cancel plans to testify to House and Senate committees on Thursday because of ill health.
''The secretary had anticipated testifying, but she is still under the weather,'' Ms Nuland said. ''She was diagnosed as having suffered a concussion after fainting and falling and her doctors have urged her to stay home this week.''
Mrs Clinton may now appear before US lawmakers in January, before she leaves office.
''She's making clear in her communication with the committee that she expects that they're going to have to have ongoing conversation in January, and she's available for that,'' Ms Nuland said.
Ileana Ros-Lehtinen, who chairs the House Foreign Affairs Committee, said it was ''unfortunate'' Mrs Clinton would not testify as planned.
Lawmakers still have ''tough questions about State Department threat assessments and decision-making on Benghazi. This requires a public appearance by the Secretary of State herself,'' she said earlier.
Mrs Clinton originally was ill after contracting a severe stomach virus on her return from a European trip this month.