|An Iraqi official says Abu Musab al-Zarqawi was caught and released last year.|
BAGHDAD, Iraq (CNN) -- Iraqi security forces caught the most wanted man in the country last year, but released him because they didn't know who he was, the Iraqi deputy minister of interior said Thursday.
Hussain Kamal confirmed that Abu Musab al-Zarqawi -- the al Qaeda in Iraq leader who has a $25 million bounty on his head -- was in custody at some point last year, but he wouldn't provide further details.
A U.S. official couldn't confirm the report, but said he wouldn't dismiss it.
"It is plausible," he said.
Thursday's news tops a list of reports of missed opportunities to capture the 39-year-old terrorist mastermind. An official said the military receives frequent reports of al-Zarqawi sightings, all of which are investigated. (View profile on al-Zarqawi)
In April, U.S. troops stormed a hospital in Ramadi based on credible intelligence that terrorists were hiding there, but no suspects were found, military officials said in early May.
A high-ranking Iraqi Army officer said there were rumors that al-Zarqawi was at the Ramadi medical center, and several groups affiliated with the al Qaeda operative issued statements saying the same.
Iraqi Lt. Gen. Nasser Abadi said Thursday that al-Zarqawi was taken to the hospital. He added that he didn't believe Kamal's report was correct.
"When we got the news, we rushed there, but he was out of there," the general said.
The Jordanian-born al-Zarqawi was almost captured in February, too, after troops received a tip that he was heading to a meeting in Ramadi, said Pentagon officials speaking on condition of anonymity.
With his vehicle under surveillance by an unmanned Predator spy plane, troops set up checkpoints along his route. As al-Zarqawi's truck approached one of the checkpoints, the vehicle abruptly turned around, the officials said.
He was chased for several miles, but when troops finally ran his vehicle down, the terrorist had escaped. His driver and security guard were arrested, and troops found a computer with a "treasure trove of information" that offered a clear indication that al-Zarqawi corresponded regularly with al Qaeda leader Osama bin Laden, the officials said.
Colin Powell first linked al-Zarqawi with al Qaeda in a February 2003 speech to the U.N. Security Council, in which he said, "Iraq today harbors a deadly terrorist network headed by Abu Musab al-Zarqawi, an associate and collaborator of Osama bin Laden and his al Qaeda lieutenants."
Before taking the moniker al Qaeda in Iraq, his organization was known as Unification and Jihad, which the U.S. State Department labeled a "foreign terrorist organization" in October 2004.
His group has taken responsibility for or been accused by the U.S. of perpetrating or aiding in numerous suicide bombings, car bombings, beheadings and other acts of violence.
Included are a February 2005 suicide bombing in Hilla that left 127 Iraqis dead, an October 2004 execution-like massacre of 44 Iraqi soldiers east of Baghdad and an August 2003 car bombing in Najaf that killed more than 85 people. Ayatollah Mohammad Baqr al-Hakim, the leader of the Supreme Council of the Islamic Revolution in Iraq, was killed in the Najaf bombing.
Al-Zarqawi also is suspected to be the masked man who beheaded Nick Berg, an American civilian in Iraq, on May 11, 2004.
In April, two Web sites posted an audio message, purportedly from al-Zarqawi, in which he urges his followers to continue their attacks on U.S. forces in Iraq and warns President Bush he will never relent