Sumendra Yadav, who works as a senior technician at the dairy, and another accused identified as Atul were arrested yesterday in the case, they said.
The dairy van which was carrying Rs 20 lakh was looted and cashier Manoj Gaur was killed near Gagan Public School on the outskirts of the city on October 8.
Yadav is allegedly the main conspirator behind the crime, they said, adding that six other accused are still at large.
