"During the course of investigation, it was found that one more person namely Mohd Ibrahim of Poonch is also involved in the murder, he was arrested today," Jammu SSP Uttam Chand said.
Two accused Rajni Devi and Sunil Kumar were already arrested by the police, he said, adding that Mohd Ibrahim was also present in the room at the time of the murder.
"After killing the girl, Ibrahim left for Poonch whereas Rajni Devi and her husband Sunil Kumar went to buy a machete which they used to chop Shivani's body to be dumped in a septic tank," he said.
"Her plan was exposed and Rajni along with Ibrahim decided to get rid of Shivani, so they also involved Sunil by luring him of money and intimidating him," the SSP said.
He said that the trio first strangulated Shivani and later chopped her body with a machete to be dumped in the septic tank.
"The police is investigating the case to gather more evidence, if any in due course case will be produced in the court of law," he said.