When a special Muzaffarpur police team barged into a college on Thursday to rescue an abducted boy, they were stunned to see that the three kidnappers were cops.

The special investigation team (SIT) arrested the trio - Somesh Singh, Sanjeet Kumar and Mohammad Akhtar, the district vice-president of the Bihar Police Men's Association - who were all posted at Ahiyapur police station in Muzaffarpur, around 80km north of Patna.

The trio were suspended and departmental proceedings initiated against them, and senior police officers also recommended dismissal from service.

Police said the trio kidnapped Shashi Ranjan, 18, a resident of Maksudpur village under the jurisdiction of Minapur police station in Muzaffarpur, from Zero Mile Chowk on Wednesday and kept him in a room of a college in Kanti, around 10km west of the district headquarters town.

The kidnappers told Ranjan's father, Umesh Yadav, to come to Kanti with Rs 5 lakh or they would kill the boy, police sources said.

Umesh, a farmer, contacted Tirhut zone inspector-general (IG) Sunil Kumar and deputy inspector-general (DIG) Anil Kumar Singh, who instructed Muzaffarpur senior superintendent of police (SSP) Vivek Kumar to take action. The SSP formed a special investigation team (SIT) headed by deputy superintendent of police Ashish Anand, which rescued the boy and took the cops into custody.

Raids are on to nab five others - Golu Kumar, Pankaj Kumar, both residents of Kanti, Rakesh Kumar, Suchit Kumar and Kiran Kumar, all residents of Kachchi Pakki locality of the town - who were keeping a watch on the hostage and managed to escape.

DIG (Tirhut range) Anil said the three cops had picked up Ranjan accusing him of being involved in an ATM fraud case.

Anil said the kidnapper-cops' services will be terminated "as the charges against them are serious".

A video showing Akhtar with a liquor mafia member had surfaced last month, police sources said.

During preliminary investigation, the cops found that the trio were also involved an ATM fraud racket - swindling money by duping bank customers - in Muzaffarpur and neighbouring districts. At least 70 such cases have been lodged at the Ahiyapur police station in the past six months.

"We will not spare anybody who brings a bad name to the police," said Muzaffarpur SSP Vivek. Sources said Somesh was transferred to Ahiyapur from the Mithanpura police station of the district two months back.