Even as Uttar Pradesh Minister Raghuraj Pratap Singh alias Raja Bhaiya resigned on Monday over his alleged involvement in the killing of a senior police officer in Pratapgarh district, sources close to the officer revealed that he had been receiving threats over his investigation of a recent violent incident.

The deceased, Zia-ul-Haque (32), the circle officer of Kunda, was probing the violence in Asthan village, where, in June, around 50 homes were flattened by a mob allegedly over the rape and murder of a 14-year-old Dalit girl. While the locals contended that they were targeted because a Muslim had become pradhan of the village, snatching the post from a Raja Bhaiya supporter, various rights groups, including the PUCL, saw the hand of Mr. Singh in the violence.

However, Raja Bhaiya had denied all the charges.

“There were attempts to put him [Haque] under pressure. He had been receiving threats to exclude some names from his report, including that of people close to the Minister and possibly him too. The last time we spoke, he told me the report was almost ready and he was going to file it in a few days. But he also talked of his plans to quit and prepare for an administrative job in the coming months, saying his job was not for honest people like him,” a friend of Haque told The Hindu on condition of anonymity.

In her complaint, the slain officer’s wife Parveen Azad alleged that her husband was killed at the behest of Mr. Singh. She also said that after his posting to Kunda, he was constantly threatened by persons close to Mr. Singh. “He [Haque] would often discuss it [the threats] with me,” she said.

A police official was quoted by the media to have said that the killing was a planned act.

While Mr. Singh was booked for conspiracy, murder charges were slapped on his aides Hari Om, Nagar panchayat president Gulshan Yadav and driver Rohit Singh. Mr. Singh denied any involvement in the incident.

In her complaint, Ms. Azad had also mentioned that her husband was assaulted with sticks and rods before being shot at point-blank range. A forensic team from Allahabad inspected the body and the bullets used in Saturday’s incident.

A report by a four-member panel of doctors had confirmed that he was first beaten up before being shot dead.