Subhash Chand, posted at Karawal Nagar police station, was deployed on law and order duty and is battling for his life at the Ram Manohar Lohia Hospital.
Chand sustained serious injuries in the protests and is still on ventilator.
"His condition is stated to be critical," a senior police official said.
Protesters and the police clashed continuously at India Gate on Sunday, in which several other policemen were also injured.
