A criminal who had lost a bet on an IPL match accepted a contract or supari, along with his fellow gang members, from a close relative of an hotelier to kill him.

Four members of the Bajrang Sahni gang — Rocky Sahni, Amit, Deepak and Chotka Sunny — were arrested from different parts of Patna on Thursday, for murdering 50-year-old businessman Hari Mohan Prasad on the night of May 22. Police recovered Rs 41,600, a knife used to stab the victim, four cellphones, a country-made pistol and a cartridge from them. Two others — Bajrang and an associate — are on the run.

Initially, police had said that robbery was the motive. But on Friday, they said the gang had accepted Rs 5 lakh from a close relative of the businessman to bump him off.

Deepak had recently lost Rs 20,000 in an IPL match bet during. Under pressure to repay the amount, he joined five other Bajrang gang members to stab to death Prasad at his Nasirganj home. The murderers also looted jewellery and money.

Patna senior superintendent of police (SSP) Manu Maharaj on Friday said: “Four of the six persons involved in the crime have been arrested. We feel that it is not just a robbery but a contract killing with the involvement of an insider in the victim’s (Prasad’s) house.”

On the night of the murder, the killers reportedly knew that the main door of the house would be open and they would not be challenged.

“The Bajrang Sahni gang has been active in Patna for a few years now. They had killed Patna High Court registrar Jai Shankar Rai at his Punaichak residence in October 2010. They had just been released from jail. Two days before killing Prasad, they had attacked the guard of an ATM kiosk in the same area while looting the machine,” said the SSP.

Businessman Prasad used to stay with wife Sunita, son Pankaj and his daughter-in-law in the house. His two other sons lived in different houses in the same locality.

On the night of the murder, Pankaj and another brother had a chat with their father on the first-floor of their two-storeyed house around 9.10 pm. The two brothers stepped out 10 minutes later. The police believe the killers knew that apart from their target (Prasad) there were only two women at the house — Sunita and Pankaj’s wife. They tied up and gagged Sunita but did not kill her.

The SSP said: “Deepak’s involvement in betting, which was an impetus to commit the crime, is another aspect we are investigating.”