Abu Usama Al-Irlandi was reportedly known to gardaí
The Department of Foreign Affairs says it is working to clarify claims that an Irish citizen has been killed in Iraq.
The Islamic State has claimed that jihadist Abu Usama Al-Irlandi was killed during fighting in the city of Mosul.
In a statement, the department says it is "aware of media reports concerning an Irish citizen in Iraq and is seeking to clarify the situation."
ISIS Twitter accounts have posted a picture of the man holding the device allegedly used in the attack.
Reports say the man was born and raised in Dublin, and he converted to Islam in 2000.
Journalist with the Irish Independent, Cathal McMahon, says the man was more commonly called Khalid Kelly.
He also says the man was known to the gardaí.