Magistrate Atul Raj Bhalavi rejected the bail plea of the school's transport officer, Chaitanya Kumavat.
After the investigation revealed that the speed-governor (which limits the speed of a vehicle automatically) installed in the bus was sub-standard, the police had arrested Kumavat.
The owner of the firm, which had installed the device, and one of its employees were also arrested, along with Kumavat, under IPC section 304 (culpable homicide not amounting to murder).
The police had said the firm had issued a fake certificate about the speed-governor (also known as "speed limiter").
The bus was running at a speed of over 60 km per hour when it broke the road divider and collided with a truck, while as per the state transport department's rules, the speed should not have exceeded 40 km per hour after the speed governor was installed in the vehicle.
Four school children and the bus driver were killed in the accident, which had occurred at the Kanadiya by-pass here on January 5.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)