A photograph of what Islamic militants claim is a captive US soldier may have been posed with a toy figure, an army doll manufacturer has said.
Dragon Models USA said the figure in the picture, posted on a website used by Islamic groups, resembles "Cody", an action toy based on US special forces.
The Pentagon said no US troops have been reported missing in Iraq.
The photograph purports to show a soldier called John Adams in desert uniform with a gun pointed at his head.
In a statement accompanying the picture, an Islamic group calling itself the Mujahideen Brigades claimed on Tuesday to have taken a US soldier hostage in Iraq.
It threatens to kill him unless Iraqis held in US-run prisons are freed within 72 hours.
But Dragon Models USA has pointed out the figure pictured has similar facial features, uniform and equipment to its product.
"For us it bears a striking resemblance," spokesman Liam Cusack told the AFP news agency.
"We want the proper authorities to check it out. Even the boots are the same shade as the action figure we made."
The company produced 4,000 of the Cody action figures in 2003, for sale at US military bases in Kuwait and the Middle East.
Staff Sgt Nick Minecci, a US military spokesman in Baghdad, told the Associated press news agency that no units had reported anyone missing.
A Pentagon spokesman said investigations were continuing into the website's claim.
The Mujahideen Brigades has previously claimed responsibility for the abduction in April of three Japanese hostages, who were later released, and a Brazilian engineer missing since January.
In August, a US man from San Francisco staged a hoax video that appeared to show him being beheaded in Iraq.
It was initially reported to have been released by militants, but Benjamin Vanderford then admitted he had made it, arguing it was designed to show how easily such videos can be faked.