Baghdadi, who suffers from diabetes, is thought to have been left unable to walk unassisted from injuries incurred from a raid in 2015 which were exasperated by another last May. Their assessment is based on reports from ISIS detainees and refugees in northern Syria, the officials added.
United States officials confirmed to CNN that while Baghdadi's injuries were not considered life-threatening they did mean he has not been able to continue to command the daily operations of the group.
"We have irrefutable information and documents from sources within the terrorist organisation that al-Baghdadi is still alive and hiding with the help of his collaborators", al-Basri said.
At the time, ISIS was about to lose control of the Iraqi city of Mosul and its so-called capital Raqqa had been almost encircled by US-backed forces. The officials told CNN they were not sure whether the injuries were a result of an attack by the US-led anti-Islamic State coalition, or by a Russian missile strike.
"There have been isolated strikes by Russians in Raqqa, but as there's no timeline to it, we don't know if it's ours", a U.S. official said.
In June 2016, Turkish media reported that al-Baghdadi had been killed in a US airstrike in Raqqa, Syria, but this was never confirmed.
In June 2017, Russia's Defense Ministry said it was investigating the possibility that Baghdadi was killed in a strike carried out by the Russian Aerospace Forces on May 28 in the southern suburbs of Raqqa.
The Iraqi official said that Al-Baghdadi, with a $25m USA bounty on his head - is now in Syria's Jazeera desert, west of Deir Az Zor.
In 2014, a video was released showing al-Baghdadi preaching during Friday prayer at a mosque in Mosul, Iraq, which was then held by ISIS.