New Delhi: A CBI employee's son has been arrested along with his friend in connection with a south Delhi restaurant owner's murder following a tiff over a bill amount, police said on Friday. Accused Manish Kumar, 25, the son of a Central Bureau of Investigation staffer, and his friend Robin Basoa, 26, are both residents of Pilanji village in south Delhi. "Efforts are on to nab two other suspects -- Sagar and Varun -- and to seize the crime weapon," Deputy Commissioner of Police Mandeep Singh Randhawa told IANS. Pappu Vasudeo Masand, 60, owner of a Sindhi eating house in Lajpat Nagar's Central Market area, was allegedly shot dead around 11 p.m. on May 23 by the four accused after a brawl over a bill of Rs.1,085, which the accused said was overcharging. The police officer said the case was cracked on the basis of the registration number of a car the four were travelling in. Kumar, a class 12 passout working as a chit fund agent, told police that they decided to kill the hotel owner after Sagar was slapped during a quarrel between them and the victim. The officer said the accused used a pistol allegedly belonging to Kumar but kept in Robin's house for safekeeping. "They reached the restaurant, fired upon the victim and escaped in their car." Robin earlier worked at a call centre at Gurgaon but left the job about six months back, the police officer said.