Saddam Hussein's cousin and feared lieutenant Ali Hassan al-Majid, known as "Chemical Ali", appeared before an investigating magistrate today, an Iraqi judge said.
Former defence minister Sultan Hashem Ahmed was also in court.
The hearings, promised by the interim government as it began campaigning for the first post-Saddam election, were the first of a new stage in the trial process that will press war crimes and other charges against Saddam and 11 others, officials said.
Mr Raed Jouhi, the chief investigating judge for the Special Tribunal set up to try the leaders of the old regime, told reporters there was no set timetable for the trials and that the other accused would also have many hearings in the investigation stage, which would determine whether to send them for trial.
Prime Minister Iyad Allawi had said last week, as campaigns began for elections next month, that "trials" would begin next week. But Jouhi stressed this was not formally the start of trial but merely a preliminary stage of the legal process.
"Hurrying will not help this case," he said.
International human rights campaigners had voiced concerns that Mr Allawi might rush trials through.
Lawyers for Saddam and the others complained they had not had access to their clients. Saddam saw a lawyer for the first time on Thursday, just over a year since he was captured on December 13th, 2003.
Majid, who earned his soubriquet for his role in using poison gas against Kurdish villagers in the late 1980s, and General Hashem were both represented by lawyers.
An official from the British embassy, which is working closely with the Iraqi interim government on the trial process, said they understood that the pair were the first of the 12 to face a judge in this way. Saddam and the others last appeared to hear the broad thrust of charges against them in July.