Police also gave clean chit to activist Vineet Tiwari, Communist Party of India-Marxist leader Sanjay Parate, and Manju Kavasi and Mangla Ram Karma, Sukma superintendent of police Jitendra Shukla said.
The tribal, identified as Shamnath Baghel, was allegedly killed by naxals with sharp weapons on the night of November 4, 2016 in Nama village under Tongpal police station limits.
As per the complaint lodged by Shamnath's wife Bimla, the ultras had accused her husband of disobeying Sundar and five others who are their "well-wishers", a police officer said.
The complainant had claimed that Sundar and others had visited Nama village and asked Shamnath to support the naxal cause, the officer said.
Based on Bimla's complaint, a case was registered against Maoists, Sundar, Prasad and four others under sections 147 (rioting), 148 (rioting, armed with deadly weapon), 149 (every member of unlawful assembly guilty of offence committed in prosecution of common object), 302 (punishment for murder), 450 (house trespass in order to commit offence) and 120 (B) (criminal conspiracy) of IPC and the Arms Act, he said.
Sundar and others were never arrested.
Shukla said a special team led by Sukma Additional Superintendent of Police Shalabh Kumar Sinha was constituted to investigate the murder.
"During the investigation, no concrete evidences were found against Sundar and five others. As per the villagers' statements and eye-witnesses, these six were not present at
the spot at the time of murder. Hence, because of lack of evidence, we have taken back the charges against them," the SP said.
Police are yet to file chargesheet in the case and may file it later this week, he said.
Shukla said Sundar and five others are being given a "clean chit", as no evidences were found against them during a probe.
"Efforts are on to trace the naxals involved in the incident. The chargesheet in the case will be filed in the court this week," he said.
The then BJP government had drawn flak from activists and educationists, after the murder case was registered against Sundar and others.
Rights activists had alleged that the then Inspector General of Police (Bastar range) SRP Kalluri was trying to falsely implicate them in various cases.
The murder case was later handed over to state Crime Investigation Department.
Sundar has welcomed the development.
"We are happy that all charges have been dropped. This was a vindictive case that was filed immediately after SPOs (special police officers) were chargehsheeted in Tadmetla
incident. An incident in which SRP Kalluri (IPS officer) had also been involved," Sundar said.
In Tadmetla area in Bastar, houses of locals were allegedly set ablaze during an anti-Naxal operation in 2011 by police personnel.
"We hope that all the other people who are in jail in Chhattisgarh and elsewhere on false charges will also be released soon," she added.
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