Adnan Pachachi, among several members of the council who were taken to see Saddam, confirmed his identity at a news conference.
"He seemed rather tired and haggard but he was unrepentant and defiant at times," said Pachachi, who was foreign minister before Saddam's Baath party took power in 1968.
"He tried to justify his crimes one way or another and said that he was a just but firm ruler," he said, flanked by other Governing Council members.
"Our answer was that he was an unjust ruler because his crimes were responsible for the deaths of thousands of people."
Pachachi said they spent 30 minutes with Saddam on what he described as a historic day.
"Iraqis...have waited for this day patiently. This tyrant has been arrested this will allow us to open a new chapter."
Pachachi said the arrest could speed a transfer of power to Iraqis but dismissed the possibility of an end to daily attacks against US troops, even though they may lose momentum.
It would also accelerate the effort to recover funds which the Governing Council says Saddam and his family and associates embezzled and transferred secretly abroad, Pachachi said.
Shia Muslim leader Adel Abd al-Mahdi said Saddam was scornful of mass graves unearthed after the fall of his government which opponents accuse the deposed leader of responsibility.
Saddam was top on the US' most-
"When we asked him about the mass graves he said those were Iranian agents and thieves...He did not appear repentant and even justified his crimes," Abd al-Mahdi said.
Another governing council member Muwaffaq al-Rubai said the trio had identified Saddam in Baghdad.
He added: "Saddam tried to justify the invasion of Kuwait and the war with Iran. It's a sick mentality and psychologists should examine his obsessions."
"He was found in a hole that was eight feet with mice and rats," he added.