Tushar Mehto (21), a student of SKIT college near Hesarghatta, was murdered on January 14.
Rohit (24), a native of Ranchi, his wife Shivani (21) and her sister Preethi who hail from Agra and their friend Varish (21), a native of Patna, have been arrested in connection with the case, the police said.
Tushar, who hailed from Patna, was residing near his college and had acquaintances with dance bar girls in the city including Shivani, they said.
The five -- Tushar, Rohit, Shivani, Preethi and Varish-- met at Rohit's house on January 14. They consumed liquor and planned to extort Rs nine lakh as ransom from Tushar's father, a contractor in Patna, on the pretext that Tushar had been kidnapped.
Though Tushar agreed to the plan initially, he later started protesting against the proposed kidnap drama. At this in fit of rage Varish stabbed Tushar in the stomach with a broken liquor bottle resulting in his death, the police said.
Later, fearing police action, the four dumped the body in a deserted area. They then started making calls to Tushar's father Pramod demanding ransom.
Pramod arrived here from Patna and lodged a complaint, police said, adding, the four were arrested and the mobiles phones and the car used by them seized.
They also recovered Tushar's decomposed body.