A doctor has confirmed the Delhi Police used a toxic chemical spray against protesters during the latest clash over India’s new controversial citizenship law.

Around thirty protesters were hospitalised after exposure to a mystery substance caused them to faint, while others complained of dizziness or nausea.

Dr Azeem treated victims at Alshifa Hospital in the aftermath and their symptoms were not consistent with those seen from exposure to pepper spray.

“Protesters are panicking and complaining of suffocation, stomach ache and pains in their abdomen and chest,” Dr Azeem said.

“One of the protesters is really finding difficulty breathing even after several medications so, he has been shifted to an ICU.”

The identity of the chemical spray is currently unknown with activists claiming it to be tear gas or even chlorine gas in low concentration.