Caretaker Bhagwan Dass, 28, was found murdered Tuesday morning in his Rajinder Nagar area office.
Firm owner Ravinder Singh informed the police about the crime.
The owner also told the police that around Rs.1.5 lakh in cash kept in the locker was missing.
"On the basis of investigation it was found that Deepak Kumar, an ex-employee, was furious over being replaced. A team laid a trap and arrested Deepak Kumar, 21, and Bunty, 22 from the same area," said Deputy Commissioner of Police Alok Kumar.
Bhagwan Dass had replaced Deepak Kumar, who was harbouring ill will against the deceased.