A team headed by Deputy Superintendent of Police (DSP) Manjit Singh caught the police official, Jagtar Singh, accepting the bribe from Gagan Kumar, they said.
The ASI, posted with the Sadar Police Station here, had demanded Rs 3,000 from the complainant, Kumar, in connection with a case, the police said.
The police have registered a case against him under relevant sections of the Prevention of Corruption Act, police said.