Police said main accused Pushpa, a domestic help, has already been arrested on September 7. The security guard was allegedly in relationship with Pushpa.
Pushpa, the guard and his friend had slit the throat of Raj Kwatra, who lived in a flat of Shipra Sun City, on September 3 and fled with jewellery, police said.
Police recovered the looted jewellery worth Rs 1 lakh from the guard, who confessed to his crime, a senior police officer said.