Expert witnesses at the trial of Saddam Hussein have said he signed the death warrants for 148 Shias in Dujail in 1982, prosecutors claim.
The defendants are charged over the killing of 148 men in Dujail
They read out a report by experts who said the signature on the orders matched the writing of the former Iraqi leader, at the resumption of his trial.
He and seven co-accused face charges over their alleged role in the killings following an assassination attempt.
Defence lawyers disputed the writing claim, before the trial was adjourned.
Saddam Hussein sat in a metal pen as the report was presented in the Baghdad court.
Prosecutors said documents with his signature also included one approving rewards for intelligence agents involved in the 1982 crackdown, according to the Associated Press news agency.
But defence lawyers claimed the experts could not be independent because they had links to Iraq's interior ministry.
They called for a new set to be appointed from any country apart from Iran.
"And Israel," Saddam Hussein shouted during the one-hour hearing, in which he was otherwise quiet.
Chief judge Raouf Abdul Rahman adjourned the trial until Wednesday to give the experts more time to study the alleged signatures of Saddam Hussein and his former head of the intelligence service, Barzan Ibrahim al-Tikriti.
At earlier hearings, Saddam Hussein acknowledged signing execution orders, saying it was his duty as president of Iraq. But he later appeared to dispute their authenticity.
Mr Tikriti also dismissed the prosecution's attempt to prove his role in the Dujail killings, saying his signature was forged.
If convicted, Saddam Hussein is expected to face the death penalty.
Earlier this month the court announced he would face new charges of genocide and crimes against humanity.
The charges relate to the Anfal military campaign against Kurds in northern Iraq in the late 1980s, in which as many as 180,000 people may have died.
The case will be tried separately.