American officials denied Saddam's allegations as "completely unfounded." Saddam, in turn, denounced those denials as "lies" and said "the marks are still there."
Six witnesses, including five who were not identified, testified during the two-day session that started Wednesday. Saddam and seven co-defendants are on trial for the deaths of more than 140 Shiites after a 1982 attempt on Saddam's life in the town of Dujail, north of Baghdad.
In a theatrical exchange becoming increasingly common at the trial, an assistant prosecutor asked to resign and the defense team threatened to walk out. Saddam also mocked President Bush's claims that Iraq had chemical weapons.
When the court gave the former leader an opportunity to cross-examine witnesses, Saddam instead used the time to expand on earlier assertions he had been abused in custody. He claimed that the wounds he suffered from the alleged beatings had been documented by at least two American teams.
CBS News correspondent Cami McCormick reports witnesses told the court that hundreds of people were tortured, imprisoned and sent to live in the desert for years - testimony that was interrupted several times by defendants whose comments centered on how their treatment by the Americans was worse.
Wednesday, Saddam told the court he'd been beaten "everywhere" on his body, insisting "the marks are still there." He did not display any marks and did not elaborate on the alleged beatings except to say some wounds took eight months to heal.
Thursday, Saddam said American denials that he was beaten could not be believed, noting that no weapons of mass destruction had been found in Iraq despite Bush's prewar claims that Saddam was harboring such weapons.
"The White House lied when it said Iraq had chemical weapons," Saddam said. "I reported all the wounds I got to three medical committees. ... We are not lying, the White House is lying."
But Investigative Judge Raid al-Juhi, who prepared the case against Saddam and forwarded it to the trial court in July, told reporters that neither the defendants nor their lawyers had ever complained about beatings. Officials never saw signs of beatings, he said.
"The defendants receive complete and very good health care by the authorities in charge of the detention. No ordinary Iraqi receives this kind of care," he said.
He did not say whether Saddam and his co-defendants were examined specifically for signs of abuse.
The first witness to testify Thursday spoke from behind a curtain and had his voice disguised. He said he was 8 during the killings in Dujail. He said his grandmother, father and uncles had been arrested and tortured, and he never saw his male relatives again, implying they had been killed.
Saddam said the court should not depend on the testimony of witnesses who were children at the time of the alleged crime, and one of his defense attorneys got the witness to admit he had not been arrested and did not see any dead bodies.
Saddam's half brother and co-defendant — Barazan Ibrahim, who was head of the Iraqi intelligence services during the Dujail killings — had a heated exchange with prosecutors, accusing them of belonging to the Baath Party, Saddam's former party, in an effort to discredit them in the eyes of Iraqis.
One assistant prosecutor threatened to resign over Ibrahim's allegations, but the judge would not allow it.
The judge at one point told Ibrahim to speed up his answer, and Ibrahim responded: "Don't oppress me. I passed through this experience in the past. During the interrogation I used to be asked questions that need one hour to answer and they wanted a 'yes' or 'no' answer. When I used to answer he used to slap me in the face while my hands were tied from behind."
Defense attorneys said one of the court guards then made threatening gestures toward Ibrahim and said they would walk out if the guard did not leave. The judge had the guard removed.
Witnesses on Wednesday graphically described how their captors administered electric shocks and used molten plastic to rip the skin off prisoners in a crackdown following an assassination attempt against Saddam.
Saddam then grabbed center stage with claims that Americans beat and "tortured" him and other defendants while in detention.
A U.S. military spokesman in Baghdad called Saddam's allegations "completely unfounded" but said "we are prepared to investigate."
The trial's chief prosecutor, Jaafar al-Mousawi, said if authorities found evidence of abuse Saddam could be transferred to the physical custody of Iraqi troops.