Cops found the weapon - a 9 mm, fully loaded service revolver - from a pond in the village. The pond, incidentally, is close to the spot where the village headman, Nanhe Yadav, was gunned down.
The Central Bureau of Investigation (CBI), which is probing the case, is still to recover the bullet that hit Mr Haque in the chest. His cellphone, which could help establish who he spoke to before he died, has also not been found.
The agency has already secured the custody of two accused persons who are close aides of former state minister Raghuraj Pratap Singh alias Raja Bhaiya, who is the state legislator from Kunda. He resigned as minister from the Akhilesh Yadav government following allegations by the policeman's wife, Parveen Azad, that he was responsible for her husband's murder.
Mr Haque was killed after he reached Pratapgarh where the village headman had been shot. An angry mob reportedly cornered him, and eight policemen who were with him allegedly abandoned him. Three bullets were fired - one killed Mr Haque; two others killed Mr Yadav's brother.