US forces say they have arrested a senior member of al-Qaeda in Iraq, the group accused of being behind some of Iraq's deadliest violence.
The US says Mashhadani is the most senior al-Qaeda leader in Iraq
The man was named as Khaled Mashhadani. He was captured earlier in July in the northern city of Mosul, officials said.
US military officials said he had told interrogators Iraq's supposed al-Qaeda kingpin, Omar al-Baghdadi, was a front.
They added Mashhadani was a "conduit" between its real Egypt-born leader in Iraq and top al-Qaeda figures globally.
"Mashhadani is believed to be the most senior Iraqi in the al-Qaeda in Iraq network," said Brig Gen Kevin Bergner.
Mashhadani is said to have told interrogators that the shadowy Omar al-Baghdadi was a "fictional role" created by the Egyptian-born Abu Ayyub al-Masri.
Separately, Iraqi police said two roadside bombs exploded in south-east Baghdad, killing at least six people and the US reported the deaths of two of its soldiers in an attack in west Baghdad on Tuesday.
An actor was used for audio tape speeches attributed to Baghdadi posted on the internet, Mashhadani is said to have told his interrogators.
"In his words, [Baghdadi's group] the Islamic State of Iraq is a front organisation that masks the foreign influence and leadership within al-Qaeda in Iraq," Gen Bergner said.
"Baghdadi, who has never been seen, is an actor. To make Baghdadi seem real, Masri swore allegiance to him, knowing he was fictitious," he said.
"Mashhadani confirmed that Masri and al-Qaeda in Iraq leaders he surrounds himself with are foreigners," he said.
The captured militant had been a leader of the Ansar al-Sunna group before joining the late Jordanian-born Abu Musab Zarqawi's group, al-Qaeda in Iraq, two and half years ago, Gen Bergner said.
Correspondents say the announcement will be seen a US attempt to reinforce the idea of non-Iraqi control of al-Qaeda in Iraq, as Islamist insurgents come under pressure from former allies in Iraq's nationalist resistance.
"He is considered a conduit between Masri, Bin Laden and Zawahiri," Gen Bergner said, referring to the Saudi- and Egyptian-born founders of al-Qaeda, who are thought to be hiding in Afghanistan or Pakistan.