Al-Douri was vice-chairman of the Iraqi Revolutionary Command Council until the US 2003 invasion
Fugitive Iraqi militant leader Izzat Ibrahim al-Douri, a former right-hand man to Saddam Hussein, has been killed, Iraqi media say.
They say he died near the northern town of Hamreen in Irbil province.
Al-Douri, 72, led the Naqshbandi Order, one of the main insurgent groups in Iraq and a key force behind the recent rise of Islamic State (IS).
He was deputy to Saddam Hussein, who was ousted when US-led forces invaded Iraq in 2003 and executed in 2006.
Al-Douri was regarded as the most high-profile official of Saddam Hussein's Baath party to successfully evade capture after the invasion, and had a large bounty on his head for years.
He was the King of Clubs in the famous pack of cards the US issued of wanted members of Saddam Hussein's regime after its defeat.
There have been reports of al-Douri's death or capture before, but correspondents says this is the most credible so far.
Iraqi forces, backed by US-led air strikes, have seized large areas from IS and its allies in recent months.
However, the jihadist group still controls swathes of northern and western Iraq, including the second city of Mosul.