Freelance journalist Mukesh Chandrakar was killed for reporting irregularities in road construction work in Chhattisgarh's Bijapur district and the murder was planned by a contractor along with his two brothers and a supervisor, as per a charge sheet filed on Tuesday.

To mislead the police, the accused dumped the journalist's body into a septic tank and covered it with a fresh concrete slab.

The 1,200-page charge sheet was filed in a court in Bijapur district.

It named contractor Suresh Chandrakar, (his brothers) Ritesh Chandrakar and Dinesh Chandrakar, and Mahendra Ramteke, Bijapur Additional Superintendent of Police Mayank Gurjar said.

Suresh Chandrakar was the main accused who planned the journalist's murder after he reported irregularities in the Nelasnar-Mirthur-Gangaloor road construction work executed by Suresh and his associates, police said.

The four accused were charged under sections 103 (murder), 238 (causing disappearance of evidence of offence, or giving false information to screen offender), 61 (criminal conspiracy), 239 (intentional omission to give information of offence by person bound to inform), and 249 (harbouring offender) of the Bharatiya Nyaya Sanhita (BNS), said Gurjar, heading the Special Investigation Team (SIT).

Gurjar said the digital and physical evidence was carefully examined during the investigation and included in the case diary.

"We will try to ensure that all four accused get the harshest punishment from the court," he added.

Mukesh Chandrakar, 33, went missing on 1 January this year. Two days later, his body was found dumped in a septic tank on a property owned by Suresh Chadnrakar in Bijapur town.

The investigation led to the arrest of Suresh, his brothers Ritesh and Dinesh, and supervisor Mahendra Ramteke within 72 hours (after the body was recovered).

The slain journalist worked as a freelancer for NDTV and ran a YouTube channel, 'Bastar Junction'.

Giving brief details of the charge sheet, police in a statement said that the contractor Suresh Chandrakar, his two brothers, and the supervisor, had planned the murder.

"The news related irregularities in the Nelasnar-Mirthur-Gangaloor road construction work done by Suresh and his associates became the main reason for the murder.

"To mislead the police, the accused had dumped the body into a septic tank and covered it with a fresh concrete slab," police stated.

The police promptly arrested all the four accused within 72 hours. The forensic team completed the investigation based on scientific and technical evidence, police said.

A total of 72 witnesses were included in the witness list, as per the release.