The accused, identified as Ram Aasre (42), fled the spot after the incident and he is still at large, said a senior police official.
According to the police, the incident was reported yesterday evening when the cousins, Sarabjeet Singh and Aasre, who worked at a garment factory, joined other workers over drinks at the terrace of the factory building.
They entered into an argument, after the others left, which soon ensued into a scuffle and Aasre allegedly attacked Singh with an iron pipe.
Later, when a cleaner went to clean the terrace, he saw Singh's body and raised an alarm. The security guard immediately informed the factory owner, who called up the police control room and reported the matter. Singh was rushed to a hospital, where he was declared brought dead, said the police official.
The police questioned the other workers and the accused was identified. A case was registered under relevant sections of IPC and he is being tracked by a police team, said the official.