An inquiry into the alleged FIR tampering at Lake police station started on Wednesday, with two cops being summoned to the office of the deputy commissioner of police, south, Rajesh Subarna.

The deputy commissioner asked officer-in-charge Debasish Baidya and sub-inspector K. N. Das what had prompted them to fold a page of the FIR book and register a new charge against Bapi Halder, a murder convict who had been arrested for assaulting three youths.

According to sources, Baidya explained to Subarna that Bapi was charged under more stringent IPC section after the injury report of victims reached the police station.

The inquiry was started after news of the hidden FIR appeared in Metro on Wednesday. Sources said that when Bapi was brought to the police station around 11pm on October 9, he was taken to the room of the officer-in-charge and offered a soft drink.

“He was not kept in the lock-up at night. In the early hours, the officers asked Bapi to sit in the lock-up for a few hours,” the source said.