About 1550 people had taken ill on October 3 after inhaling the noxious fumes released by the chemical.
"Bala started dumping chemical in a nullah in Bhagirathpura area. He fled soon after the chemical started emitting gas," he said.
Police have announced a reward of Rs 10,000 each for information on the owners of the tanker and the warehouse.
The residents of settlements adjoining the nullah in Bhagirathpura area had complained of burning sensation and itching in their eyes. Several people had complained of vomiting and watery eyes.
Around 1550 people were treated at special camps organised in Bhagirathpura area.
A case has been registered under section 308 (Attempt to commit culpable homicide) and other sections of the IPC.
Further investigation is underway.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)