The men, held in the northern city of Kirkuk on the eve of the case reopening, allegedly had written orders from Saddam's former deputy, Izzat al-Douri, to assassinate Judge Raed Jouhi, who prepared the case against Saddam.
The suspects, all Sunnis, are said to have been armed with bomb-making equipment and maps with the home of Judge Jouhi marked out. A police captain, Anwar Khader Mohammed, said: "We found a letter. After interrogation they confessed to having plotted to kill Raed Jouhi."
The timing of the announcement of the alleged plot brought claims from some Sunni leaders that it was a propaganda exercise.
Today the court, set up in the annexe of a Baath party office in Baghdad, will hear from the first prosecution witnesses about the deaths of 140 Shia villagers at the town of Dujail in 1982 which followed an attempted assassination of Saddam.
The trial of Saddam has been mired in violence and fear. Eight people associated with the proceedings have been killed. Thirty witnesses due to give evidence on the opening day, 19 October, failed to turn up because they were too afraid.
Defence lawyers, who have lifted their threat to boycott the trial, said they will seek a second postponement of proceedings when the court reconvenes today. One of the lawyers, Khames Hameed al-Ubaidi, claimed it had been impossible to prepare for the trial because of the security threat. "How can we work properly when there are men trying to kill us?" he said.
The defence team will be joined by Ramsey Clark, the former US attorney general. "Our plan is to go to court in Baghdad representing the defence counsel as defence support," he said. "A fair trial in this case is absolutely imperative for historical truth."
But an American government official said no official application has been filed for a non-Iraqi to be present in court.
The case resumes just days after Iyad Allawi, the American-sponsored Prime Minister of Iraq after the invasion, said human rights abuse in Iraq was as bad as it was during Saddam's rule with "death squads" linked to the government carrying out extra-judicial killings.
Two lawyers acting for the defence have been murdered and another has fled the country after being shot. Their colleagues blame paramilitaries linked to the government for the attacks.
The Iraqi government, and US officials, maintained that the defence teams have been offered security but have refused. Khalil Dulaimi, Saddam's chief lawyer, riposted: "It is the interior ministry that has offered to provide us with protection against these attacks, but it is the ministry itself that is planning the killings."
It is not just the defence team that has been targeted. Among those who have been killed are one of the judges and his son, the brother of the chief prosecutor and three court officials.
The attacks have led to international jurors questioning whether anything like a fair trial can take place. Richard Goldstone, the first prosecutor at the International Criminal Tribunal for Former Yugoslavia, believes the court should be moved. "I don't understand how you can have a fair trial in this atmosphere of insecurity," he said. "It is just impossible to have a public trial if you can't guarantee the safety of witnesses, judges or defence counsel.
"Unless the security situation improves radically, I cannot see any possibility of having an appropriate trial in Baghdad. [It] should be held in some neighbouring Arab country."
Richard Dicker, an international law specialist with Human Rights Watch, said: "The murders of two defence lawyers demonstrates the urgent need to protect those lawyers as well as witnesses. However, all arrangements for witness protection must be consistent with fair trial guarantees."