According to the post mortem report, no rape was committed, but the woman suffered injuries on the head and near the eyes in the incident which occurred after she boarded the three-wheeler to pick up her six-year old daughter from school at Boginadi in Lakhimpur district on November 22, police sources said.
The FIR had alleged that the woman was raped by four men in the tempo who gouged out her eyes, injured her in the head and neck before throwing her out on the national highway about 50 meter away from Boginadi police station.
He was arrested under section IPC 302 (murder) and 376 (wrongful confinement), they said.
During interrogation Chetia confessed that he and the woman were in a relationship for the last two years, but denied that he was involved in her killing, they said.
The Home Department formed a Special Investigation Team (SIT) during the day as announced by Chief Minister Tarun Gogoi yesterday.
Based on media reports, the Assam State Women Commission had also taken up a suo moto case.