The head of the union of Ashrafs, Al-Sherif Najeh Muhammad Hassan al-Faham al-Aaraji admitted that the ousted president had been able to cheat despite the great value and honour attached to the line which is guarded in Baghdad.
The Ashrafs guard the Prophet's genealogical tree.
"Saddam had forced the origin experts to falsify his genealogical tree so that it went back to the Prophet," he said.
Book of origins
"We will inform all the experts, and particularly those who yielded to Saddam and agreed to falsify his genealogical tree," he said.
Aaraji showed a photo of Saddam's tree including a large book of origins which go back to the Imams Hassan and Hussein, sons of the Imam Ali bin Abi Taleb by his wife Fatima, a daughter of the Prophet.
The cancellation of Saddam's noble lineage was decided three days after his capture by US forces on Saturday night near Tikrit, in northern Iraq.
"The first committee of Ashrafs was set up in Kufa (Iraq) in 830 in the era of the Abbasids"
Ahmad Khoder al-Abbasi,
Arab committee of origins
The Ashrafs' union was set up after the fall of the old government on 9 April by the men who under Saddam were part of councils of the Sayeds, or lords, descending from Hassan and Hussein.
The union has the backing of religious dignitaries from all Muslim traditions, including the Hawza Shia seminary in Najaf, Aaraji said.
On Tuesday the union held its first congress "to build the new Iraq", attended by Sunni and Shia Ashrafs, representatives of the interim Governing Council and other Iraqi communities.
"The first committee of Ashrafs was set up in Kufa (Iraq) in 830 in the era of the Abbasids," said Ahmad Khoder al-Abbasi, head of the Arab committee of origins.
It moved to Baghdad, which became a centre for similar committees from the Arab and Muslim world. In the 1800s, the Ottomans suspended its activities and in 1917 the British scrapped the union totally, Abbasi said.