Abu Malik, a chemical weapons expert who shifted to the Islamic State after working with the Al Qaeda and the previous Saddam Hussein government, has been killed in Iraq in a US strike.
Malik was taken out in an air raid near Mosul last Saturday, and his death is expected to "degrade and disrupt the terrorist network and diminish ISIL's ability to potentially produce and use chemical weapons against innocent people", the US Central Command said.
Abu Malik earlier worked at the Muthana chemical weapons production facility under Saddam Hussein's rule, before joining the Al Qaeda in 2005, and is said to have the ability to create deadly chemical weapons for the Islamic State, which he joined last year.
"Based on his training and experience, he was judged to be capable of creating harmful and deadly chemical agents," a defence official told AFP.
The Islamic State has been harbouring ambitions of using chemical weapons in its quest for expansion, and has allegedly used mustard gas and chlorine gas on civilians on several occasions.
"We know ISIL is attempting to pursue a chemical weapons capability, but we have no definitive confirmation that ISIL currently possess chemical weapons," the official said.
According to British military expert Hamish de Bretton-Gordon, the Islamic State has the ability to make 'dirty bombs', radiological dispersal device (RDD) that combines conventional explosives, such as dynamite, with radioactive material.
He had said that the ISIS could access stockpiles of mustard gas and sarin gas, that are used as chemical weapons.