"Saddam's trial will start right after the October referendum between 16 October and at the latest October 20," said the official, who spoke on condition of anonymity because he is not authorised to make the official announcement.
The official spoke after government spokesman Laith Kubba announced that Iraq had carried out its first executions since is Saddam was ousted in 2003. Three men were hanged at 10am in a Baghdad prison for murdering three policemen.
US officials scrapped the death penalty in 2003 but Iraqi authorities reinstated it after the transfer of sovereignty so they would have the option of executing
Saddam if he is convicted of crimes committed during his regime.
European Union countries have distanced themselves from legal proceedings against Saddam, refusing to provide forensic and other assistance, because of the prospect that Saddam may be executed.
Iraqi authorities plan a series of trials for specific alleged offenses rather than lumping them altogether. The first trial will focus on the alleged massacre of hundreds of Shias in Dujail in 1982 following a failed assassination attempt.
Separate trials are expected for the gassing of the Kurds at Halabja and the 1991 suppression of the Shia uprising in the south, will be held later, officials said.
The government announced that the three men hanged on Thursday had been sentenced to death by a court in Kut last May. The government statement said they were convicted of killing three police officers, kidnapping and rape.
Iraqi officials say about seven other people, including one woman, have been sentenced to death but their cases are still under review or appeal.
Death sentences must be approved by the three-member presidential council headed by President Jalal Talabani, who opposes capital punishment. Talabani refused to sign the authorisation himself but his office said he had authorised one of his vice-presidents, Adil Abdul-Mahdi, to do so for him.