A video posted on the Internet shows what is said to be Iraqi militants beheading a man they say is an American ClA agent.
But U.S. officials say the Central Intelligence Agency has accounted for all its agents and that none are missing.
The poor quality video shows a group of masked gunmen posing around an apparently drugged or injured man seated in a chair. The victim has an identification badge that says visitor and is decapitated. It is not clear if the victim is one of the hostages that have been seized by militants in Iraq.
Earlier Wednesday, militants in Iraq freed a Jordanian man they had recently abducted.
Information for this report is provided by AP, AFP and Reuters.