Deputy Islamic State leader Ayad al-Jumaili is believed to have been killed in an Iraqi air strike near the Syrian border, according to intelligence reports.
Isil's second-in-command was reported to have been killed with other Islamic State commanders in a strike carried out by the Iraqi air force in the region of al-Qaim, near the border with Syria, on Saturday, a military intelligence source said.
The US-led coalition said it was unable to immediately confirm reports of the death of al-Jumaili, believed to be the deputy of Abu Bakr al-Baghdadi.
Iraqi state television reported the death, citing a statement from Iraqi military intelligence, which also described Jumaili as Isil's "minister of war".
Jumaili was an intelligence officer under Saddam Hussein and more recently ran Isil's top security agency in Iraq and Syria, answering directly to Baghdadi, according to experts.
"The air force's planes executed with accuracy a strike on the headquarters of Daesh in al-Qaim .. resulting in the killing of Daesh's second-in-command...Ayad al-Jumaili, alias Abu Yahya, the war minister," state TV said earlier, citing a statement from the directorate of military intelligence.
Iraqi forces, backed by a US-led coalition, have been battling since October to retake the city of Mosul, Islamic State's last major stronghold in Iraq and the city where Baghdadi declared a caliphate nearly three years ago.
Nearly 290,000 people have fled the city to escape the fighting, according to the United Nations.
US and Iraqi officials believe Baghdadi has left operational commanders with diehard followers to fight the battle of Mosul, and is now hiding out in the desert with senior commanders.
A separate battle is in preparation in Syria to drive Islamic State from its stronghold there, the city of Raqqa.
The Iraqi state TV report is the first by an official media to announce the death of Jumaili
The last official report about Baghdadi was from the Iraqi military on February 13.
Iraqi F-16s carried out a strike on a house where he was thought to be meeting other commanders, in western Iraq, near the Syrian border, they said in a statement.
More than 40 leading members of the group have been killed in coalition air strikes, according to experts.
Baghdadi has not officially appointed a successor.