Mohammed Hamza al-Zubaidi, the former Iraqi prime minister who was on the US military's list of the 55 most-wanted Iraqis during the war, died at a US military hospital on 2 December, said Lieutenant Colonel Guy Rudisill, spokesman for detainee operations in Iraq, on Monday.
The US military had issued a statement about the death of an individual on Saturday, but did not refer to al-Zubaidi by name.
"A 67-year-old male security detainee was pronounced dead by the attending physician at the 344th Corps support hospital at 7:30 a.m. on Dec 2," is all that the statement said.
His identity became clear only when Saddam's half-brother, a co-defendant in a trial for crimes against humanity, revealed al-Zubaidi's death during a courtroom complaint on Monday about what he said were poor medical facilities for detainees.
Barzan told the judge that he himself was suffering from cancer and was not receiving proper medical treatment.
Al-Zubaidi was on the US list of
the 55 most-wanted Iraqis
He said he did not want to end up like al-Zubaidi and five other senior members of the former regime who he said had died in custody.
It is not clear what al-Zubaidi died of or where he was being held before being taken to the hospital for treatment.
As a high-profile prisoner, it is likely that he was being held at Camp Cropper, a small prison near Baghdad airport where Saddam and other key prisoners are also believed to be held.
Al-Zubaidi was the commander of the middle Euphrates region before the US-led invasion of Iraq in 2003.
He was named prime minister in 1991 after Iraq's defeat in the Gulf war, but relieved of the post two years later. He was later a deputy prime minister.
After the Gulf war, when Iraq's Shia Muslim majority rose up against Saddam, al-Zubaidi, himself a Shia, was credited with having put down the revolt, when thousands of Shia Muslims were killed by the government's security forces.