Saddam Hussein's chief deputy, who has eluded capture since the U.S.-led invasion of Iraq three years ago, purportedly called for Arab leaders to back Iraq's Sunni-backed insurgency, in an audiotape broadcast Monday.

Izzat Ibrahim al-Douri, former Iraqi President Saddam Hussein's second-in-command, arrives in Damascus from Qatar, in this March 6, 2003, photo. [AP]

The tape, which Al-Jazeera television said was made by Izzat Ibrahim al-Douri, appeared to be an address to the Arab League summit in Khartoum, Sudan, this week.

The voice on the tape said Iraq's Sunni-led insurgency was "the sole legitimate representative of the Iraqi people." It was impossible to determine the tape's authenticity.

Al-Douri was sixth on the U.S. deck of cards that enumerated the most-wanted members of Saddam's regime. He had been Revolutionary Command Council vice chairman and a longtime Saddam confidant.

The voice also said Arab leaders should "boycott the regime of mercenaries and treason and besiege it by taking the necessary decision to support the people of Iraq, its courageous, national resistance and its jihad until liberation."

The tape also sought to distance the insurgency from attacks on civilians and religious targets, calling them "the pinnacle of lowliness, vileness and criminality. Our people and your resistance will take revenge from the culprits sooner or later."

Al-Douri, who is at least 62, was among Saddam's oldest and closest associates.

As the insurgency spread, the United States and its allies offered a $10 million reward for information leading to al-Douri's capture.

It was unclear whether al-Douri, who had been in poor health for years, still had a direct role in leading the insurgency. In June, the Iraqi government said he was losing influence among the pro-Saddam wing of the rebellion.

Various reports of his death and capture have proven incorrect in the past.