Sub-Inspector Manoj Singh died following gunshot injuries in Nagar Police Station here on May 19 last year. Police had then described it as a case of suicide.
Singh's wife Manisha had alleged he was murdered and demanded lodging of an FIR against the then SHO Tribhuvan Prasad.
A case of murder had been registered yesterday against Prasad, sub-inspector J P Saroj, clerk Jatashanker Tewari and three others, SHO Bhanu Pratap Singh said.
The FIR was filed after intervention of senior police officers, he said.
