Washington ? After being secretly held by the CIA for months, an Iraqi who was one of al-Qaida’s most senior and experienced operatives has been shipped to the Guantanamo Bay military prison for terror suspects, officials said Friday.

Abdul Hadi al-Iraqi is believed responsible for plotting cross-border attacks from Pakistan on U.S. forces in Afghanistan, and he led an effort to assassinate Pakistan’s president, Gen. Pervez Musharraf, and U.N. officials, the Pentagon said.

The transfer of al-Iraqi, said to have been an associate of al-Qaida leader Osama bin Laden, makes him the 15th so called “high-value” detainee known to be handed over to military officials at the military facility in Cuba from CIA control.

The arrangement continues to be controversial. People in the secret prisons are subject to harsh interrogation methods that human rights groups say amount to torture.

The Bush administration says the methods are legal and the interrogation are necessary to protect the U.S. from attack.

The Pentagon said al-Iraqi was born in 1961 in Mosul, in northern Iraq, and served in Iraq’s military. Spokesman Bryan Whitman said he was a key al-Qaida paramilitary leader in Afghanistan in the late 1990s, and in 2002-2004 led efforts to attack U.S. forces in Afghanistan with terrorist forces based in Pakistan.

Neither Whitman nor CIA spokesman Paul Gimigliano would say where or when al-Iraqi was captured or by whom.

A U.S. intelligence official, speaking on condition of anonymity because of the sensitivity of the matter, said the Iraqi man had been captured late last year in an operation that involved many people in more than one country.