Charges against 145 persons have been framed after interviewing 300 witnesses by the Haryana Police.
"The chargesheet was filed last week. It was found that the violence was not instigated from outside but was due to the union trying to show solidarity with workers," Deputy Commissioner of Police Maheshwar Dayal said.
"It was more of an internal issue between the management and the workers," he said, adding that involvement of Naxal elements into the violence was also ruled out.
When contacted, a Maruti Suzuki India spokesperson declined to comment.
Dayal further said: "Chargesheets have been filed against 145 persons and a total of 300 witnesses were interviewed to file the report, which runs into 3,000 pages."
The main charges levelled include murder, attempt to murder and destruction of property. The finding of the SIT is contrary to what the company had stated at the time of declaring a lockout at the plant, that the "orchestrated" violence appeared to be instigated from outside as "there were no pending issues with the workers".