On Sunday, monitoring group the Syrian Observatory for Human Rights said the IS leader had been “clinically dead” for several days.
Last year, the US offered a $5m (£3.5m) reward for Shishani. Defence officials said Omar Shishani died from injuries sustained in a recent US air strike in north-eastern Syria.
The Pentagon has confirmed a senior commander of so-called Islamic State (IS) is dead. Earlier reports had suggested Shishani, a Georgian whose real name was Tarkhan Batirashvili, may have survived the attack on a convoy.
Several of his bodyguards were killed in the same bombing.The strike took place on 4 March near the north-eastern town of Shaddadi, where Shishani had reportedly been sent to bolster local IS forces.
