Police said, the Class IX student B Yakub of Korkunda in the district had suffered severe burn injuries during road construction work on June 1.
A police team from Malkangiri conducted a raid at Jeypore in adjoining Koraput district and arrested contractor Abhay Swain today, Inspector-in-charge of Malkangiri police station, Raj Kishre Dash said.
Dash said the boy had been first admitted to a local hospital immediately after the mishap and later shifted in a private hospital at Visakhapatnam.
The boy, whose one hand had to be amputated to prevent the infection from spreading, was now doing better at Visakhapatnam where the district child protection officer Narayan Das and Assistance Labour Officer Subash Mandal were both camping.
Odisha Chief Minister Naveen Patnaik expressed concern over the incident and sanctioned Rs one lakh from the CM's Relief Fund, District Child Welfare Committee Chairman Santosh Kumar Nayak said.