The incident allegedly took place when Havildar Nimai Charan Sahu entered Congress Bhavan in a bid to nab some people who tried to set afire a city bus carrying passengers.
"Finding me alone, 10-12 people caught hold of me and beat me up. They hit my face and body," alleged Sahu who was later rescued by other police personnel.
The incident followed a road blockade by Congress workers protesting police lathicharge on their student activists near Naveen Niwas, the residence of Chief Minister Naveen Patnaik.
As some of the agitators who tried to set afire a bus fled the spot and entered the nearby Congress Bhawan, havildar Sahu had rushed there.
Meanwhile, Odisha Pradesh Congress Committee (OPCC) president Niranjan Patnaik condemned the police excess on the student wing activists. "We will stage a statewide agitation against this police action," Patnaik said.
The issue was also raised in the state assembly.