ISIS chemical weapons expert killed in US-led air strikes

A chemical weapons expert who once worked for longtime dictator Saddam Hussain and was preparing to defend the biggest city in the Islamic State with poison gas has been killed in a US-led air strike in northern Iraq.

Salih Jasim al-Sabawi alias Abu Malik was killed in an air strike near the ISIS-held city of Mosul on January 24, The Telegraph reported.

Malik, who is believed to have worked for Saddam's poison gas programme before it was dismantled in the 1990s, may have been tasked to prepare poison gas to hold Mosul, it said, quoting Hamish de Bretton Gordon, former commander of the British Army's defences against chemical and biological weapons.

Mosul is the biggest city in northern Iraq and the largest population centre in ISIS' hands.

"In my opinion, ISIL will do anything to avoid losing Mosul," he said. "Malik will have had the technical knowledge to be able to make chemical weapons."

Malik, a "chemical weapons engineer", was part of al-Qaeda's network in Iraq from 2005 after Saddam's downfall. He later joined the ISIS.

"He joined ISIL and his past training and experience provided the terrorist group with expertise to pursue a chemical weapons capability," the US Central Command said in a statement.

His death would "diminish ISIL's ability to potentially produce and use chemical weapons," it added.