The Bengaluru Police said on Friday that they arrested nine people — including three prison warders and four inmates — in connection with three separate cases involving the possession, use, and alleged smuggling of mobile phones into Bengaluru Central Jail at Parappana Agrahara.The arrests followed an investigation that began with a phone and SIM card seizure from inmates Prajwal Revanna, former Hassan MP and convicted sexual offender, and Prathap Rai, and which has since uncovered the involvement of prison staff and warders in exchanging phones between inmates for money.Preliminary findings indicated that the SIM card the former MP used had been active since March.On August 11, acting on the directions from senior officers, the Central Crime Branch (CCB) police conducted a surprise inspection of barracks in the prison’s Security Division and recovered one mobile phone, a SIM card, a charger, and a notebook from a cell occupied by undertrial prisoner Prathap Rai and convicted prisoner Prajwal Revanna.The police registered a case and subsequently took five people into custody on different dates for allegedly purchasing the seized phone and SIM card and helping smuggle them into the prison.How the phone and SIM card got inDuring interrogation, accused Naveen Kumar said he had purchased the phone, which was then passed on to undertrial prisoner Manjunath, who is facing a murder case. Naveen Kumar allegedly handed the phone to prison warder Prakash Gawade, who is suspected of facilitating its entry into the barracks.The police said such phones, worth around Rs 10,000 outside, are resold among inmates for anywhere between Rs 75,000 and Rs 2 lakh, with the actual transactions taking place outside the prison. That markup has led investigators to suspect the involvement of frisking staff as well.Story continues below this adAlso read | Can prisoners have a mobile phone in open jail precincts?: Delhi HC seeks clear SOPThe SIM card, the police said, was arranged for undertrial prisoner Mohammed Tauseef by Sadiq, the son of a fellow prison inmate, who purchased it in Bengaluru. The SIM — registered in Andhra Pradesh and used while roaming in Karnataka — was allegedly handed to Tauseef when he was taken to Victoria Hospital for treatment after complaining of fever.“The SIM card was wrapped in carbon paper and sealed with cellotape, and was concealed in Tauseef’s mouth. The hand-held metal detector used during frisking failed to detect it, allowing him to take it inside the prison,” a senior police officer familiar with the investigation told The Indian Express.The police said the smuggling occurred sometime after April, and that such SIM cards typically change hands inside the prison for Rs 7,000-Rs 8,000.Investigators say the phone and SIM recovered from the cell were being used by Prathap Rai and Prajwal Revanna.A wider network: 2 warders linked to 20 phonesStory continues below this adSeparately, the police also probed the alleged role of two prison wardens in facilitating the entry of around 20 prohibited mobile phones into the prison over the past year. These allegations emerged from two other cases in which investigators traced the phones using SIM and technical data.In the first, four mobile phones, two SIM cards, and a charger were recovered following a complaint from the Superintendent (in-charge) on January 13. The police traced two Airtel SIM cards through the Central Equipment Identity Register (CEIR), allegedly linking two of the phones to warder Srinivas Naik. Naik, arrested on August 28, reportedly told the police he had purchased phones under the fictitious name “Rahul” and had procured around 12 phones in total for supply to inmates.In the second case, a mobile phone and SIM card recovered on August 20 were traced through sales records tochief warder Vijay Kumar, also arrested on August 28.The police said technical evidence and questioning indicate the phone was procured on the instructions of inmate Bharat, alias KTM Bharat, with Vijay Kumar allegedly facilitating its entry.ArrestsStory continues below this adNaveen Kumar, Manjunath, Sadiq, and Mohammed Tauseef were produced before court and remanded in judicial custody on August 24.Warder Gawade was arrested and remanded on August 24, while warder Srinivas Naik and Chief warder Vijay Kumar were produced before court on August 29 and remanded in judicial custody.Undertrial Prathap Rai and Prajwal Revanna were sent into three days’ police custody for interrogation and sent back to prison on September 10.The police are investigating whether other prison staff or inmates were involved and examining the role, if any, of personnel responsible for frisking in facilitating the alleged smuggling of prohibited items into the prison.Story continues below this adAccording to prison department data, nearly 300 mobile phones have been seized from prisons across Karnataka since the beginning of this year.