Gurugram, Dec. 12 -- Three men from Delhi were arrested for allegedly murdering a 23-year-old man by making him drink beer laced with rat poison and later smashing his face to prevent identification, police said on Thursday. Investigators believe the killing was driven by revenge, after the victim allegedly sexually harassed the sister of one of the assailants. The three suspects - Ranjeet Gupta, 24, and Sonu Tiwari, 25, both residents of Okhla, and Rajeev Kumar, 22, of Karpuri Thakur Jan Jivan Camp - were arrested from the Palwal-Uttar Pradesh border on Monday night, police said, adding that they were remanded to two days of police custody for interrogation. The victim, identified as Sumit Mit, was originally from Madhubani in Bihar and had been living with his uncle's family in Okhla Phase-I. According to police, the suspects invited Sumit for drinks in Okhla on the night of December 3. Ranjeet allegedly mixed rat poison into the beer. When Sumit lost consciousness, the three men drove him in a Maruti Eeco van to Palwal via the Badarpur border. He was murdered between 3am and 4am on December 4, investigators said. Villagers discovered Sumit's disfigured body on December 6 in bushes near NH-19 close to Khatela village in Palwal's Hodal. His face had been smashed, apparently to delay identification. Sub-inspector Tejpal, station house officer of Mundkati police station, said the body initially remained unidentified, but by Saturday night police were able to confirm his identity and inform his uncle, who then filed a murder complaint naming Ranjeet as a possible suspect. A police officer involved in the investigation said Ranjeet had gone into hiding after the murder. Once arrested, he allegedly confessed that Sumit had repeatedly sexually harassed his sister. Ranjeet claimed he had confronted Sumit earlier, warning him to stop, but the harassment continued. According to Tejpal, Ranjeet also alleged that he had lodged a complaint with Delhi Police but no action was taken - a claim that police said they are verifying. Police said Ranjeet then decided to "teach Sumit a lesson" and enlisted Sonu and Rajeev in the plan. They allegedly purchased rat poison, pretended to organise a liquor outing, and lured Sumit into the van. After poisoning him, the trio drove to Palwal. Once Sumit was unconscious, they dragged him nearly 200 metres off the highway, where Ranjeet allegedly struck him repeatedly with stones and bricks. During custodial interrogation, police recovered Sumit's phone, which Ranjeet had dumped near the murder site, and also seized the Eeco van used in the crime. Further investigation is underway, officers said....