Izzat Ibrahim al-Douri was killed when Iraqi security forces raided a safe house between Hussein’s ancestral home of Tikrit and Kirkuk, according to the report.

Al-Douri, the red-haired former general and senior Baath Party official, managed to evade capture for a dozen years after a U.S.-led invasion toppled Hussein’s Sunni-led government in 2003.

He was the highest-ranking fugitive — the King of Clubs, or No. 6 — listed on the deck of cards that U.S. commanders issued in 2003 for the most-wanted regime leaders.

“He was big because he was the guy who orchestrated the transfer of billions of dollars out of Iraq to Syria for the purpose of bank rolling insurgency activities,” said Paul Hughes, a retired Army colonel who advised the U.S.-led Coalition Provisional Authority that administered Iraq immediately after Hussein was toppled. “There were a lot of reports over the years they got him. I am still waiting to hear that the DNA has been tested before I am ready to believe this guy is dead again. But if they got a guy with a big read beard then it sounds like him. And it appears the age is about right. He is in his early 70s.”

“I have been waiting for that [expletive] to die,” he added.

It was not immediately clear who killed him, however, though reports out of Baghdad and the nearby Kurdish regions suggested a Shia Militia was responsible.

Judith Yaphe, a former CIA Iraq analyst, said the potential suspected groups are several, including the Islamic State of Iraq and the Levant itself, which she said has appeared to have taken revenge on some former Hussein loyalists who joined the group but then became disaffected.

“He probably brought the disgruntled Iraqi army officers into ISIL. Some tried to quit. You do not quit. … It raises in my mind the question who killed him? Maybe [ISIL] killed him,” Yaphe said.

According to the news reports, Iraqi officials were transferring to Baghdad a body of someone who closely resembled the light-complected and mustachioed commander for DNA testing.

“We are not 100 percent sure that the body belongs to Izat al-Douri,” a security official told NBC News. “The government will do fingerprints and DNA tests in order to be sure that the one who was killed is Izzat al-Douri … We have to double confirm this.”

A spokesman for the U.S. Central Command said he could not confirm the report, saying only, “We are certainly aware of who he is and the role he has played within the Hussein regime.”

Recent reports from the region indicated that al-Douri, who was believed to have financed the Sunni insurgency, had aligned with ISIL, even though the Baath Party had been mostly secular.

His alliance with ISIL, which is also seeking to topple the Shia-led Iraqi government, has underscored how the radical group has relied on a number of shifting alliances — religious and secular — including with military officers who fled after the 2003 invasion and waged an insurgency against the U.S.-led coalition.

In a number of messages and videos over the years, al-Douri urged Iraqis to resist the Shia-led Iraqi governments that replaced Hussein and have allied with neighboring Iran.

In one message in early 2013, he urged: “The people of Iraq and all its nationalist and Islamic forces support you until the realization of your just demands for the fall of the Safavid-Persian alliance,” referring to a Shia Muslim dynasty in Iran during the 16th to 18th centuries.

There have been indications that al-Douri and “members of Saddam’s former army” have been present in Iraq’s second largest city, Mosul, an ISIL stronghold, and may have been involved in the ISIL seizure of Tikrit, which was retaken by Iraqi forces, backed by U.S. airstrikes earlier this month.

Analysts believe the group of former Iraqi officers is a reference to the Baathist Jaysh Rijal al-Tariqa al-Naqshabandia, or JRTN, which al-Douri was believed to have commanded.

“Many residents of Mosul seem to believe that ISIS does not, in fact, have full control of the city and that ‘members of Saddam’s former army’ are present,” according to an analysis produced last year by the Institute for the Study of War, a Washington think tank with close ties to top U.S. and Iraqi military and intelligence officials.

“There are also rumors that Izzat Ibrahim al-Douri, a senior member of Hussein’s inner circle, is now commanding the rebel elements in Mosul. Given al-Douri’s position in JRTN, this rumor is intended to signal the significance of Mosul to the group,” the analysis said.

“Reports indicate,” it added, that “al-Douri supporters are active in Mosul and Tikrit, but we are not able to assess the extent of this activity with any confidence at this point.”

Under Hussein, al-Douri was deputy leader of Iraq’s Revolutionary Command Council. He took over the Baath leadership after Hussein was executed by the Iraqi government in 2006. Born around 1942, he was from the same clan as the ousted Iraqi dictator and was among those who plotted the overthrow of the Iraqi government in 1968 that returned the Baath Party and brought Hussein to power.

“Saddam didn’t see him as a threat,” said Yaphe. “He was seen as religious and also strong in the party. He headed a militant order made up of party people. They were very militant. They supposedly practiced odd rituals. Bloody ones.”

His daughter was married to Uday Hussein, one of Hussein’s sons who was killed by U.S. forces in 2003.

He has been widely believed to have battled — or even succumbed to — serious illness over the years.

According to a profile compiled last year by GlobalSecurity.org, an Alexandria, Virginia, think tank, “There are contradictions about his health, and there are some reports that he’s trying to put out false information purposely. It is said that he suffers from leukemia and undergoes blood transfusions every six months for treatment. In 1999 he visited Vienna, Austria, for treatment of leukemia. The Austrian opposition demanded that he be arrested for war crimes, but the government allowed him to leave the country.”

The report added that al-Douri’s whereabouts remained “difficult to pin down, but many observers in Syria believe he traveled in and out of Syria frequently.”

Following the 2003 invasion, al-Douri frequently took advantage of Islamic terrorist groups to advance his stated agenda of returning the Baath Party to power in Baghdad. He and his followers from the ousted Iraqi Republican Guard took advantage of Al Qaeda’s bloody and high-profile campaign against the Iraqi government and the U.S.-led coalition.

“The entire underground ex-Baathist regime and its commander, Gen. Izzat Ibrahim al-Douri, were reduced to near-invisible status on the world stage,” Malcolm Nance wrote in the book “The Terrorists of Iraq.” “This served the [former regime loyalists] well. [They] could perform all of the combat actions against the Americans and nearly always rely on the fact that many were being attributed to [Al Qaeda in Iraq’s] foreign fighters.”

Added Hughes: “If he had all that money he didn’t need to be in the limelight. He could stay in the background. This guy didn’t survive the Saddam years by being stupid.”

Jen Judson contributed to this report.