LUCKNOW, May 22 -- The investigation into the murder of Chandranath Rath, personal assistant to West Bengal chief minister Suvendu Adhikari, took a dramatic turn after the Central Bureau of Investigation (CBI) gave a clean chit to Ballia resident Raj Singh, 28, whom the West Bengal Police SIT had arrested on May 10. Singh was released after the CBI found he had been mistakenly detained due to confusion over his name with that of the alleged main shooter Rajkumar Singh. The CBI took over the case investigation after registering a separate FIR in the matter on May 11. Simultaneously, the CBI tightened its net around the alleged conspiracy by arresting an arms supplier linked to the accused shooters. Officials said the mistaken arrest stemmed from the initial investigation after Kolkata Police detained two suspects - Vicky Maurya and Mayank Mishra - from Bihar's Buxar district. During questioning, the name "Raj Singh" surfaced, prompting UP Police to detain Raj Singh from Ayodhya and hand him over to Bengal Police. Sources said Raj Singh was returning from Lucknow after attending a wedding function linked to a legislator when police arrested him. His photographs with BJP leaders later circulated widely on social media, fuelling political speculation around the case. He was released from Kolkata jail on Wednesday after receiving a clean chit in the case. The CBI subsequently identified Rajkumar Singh, also a Ballia resident, as the alleged main shooter and arrested him from Muzaffarnagar on May 18. As the probe progressed, the UP STF, assisting the CBI, arrested Naveen Kumar Singh from Ballia for allegedly supplying weapons used in the murder conspiracy. STF officials said Naveen Kumar Singh was taken into custody from Bisunpuri crossing. During interrogation, the accused allegedly disclosed that on May 7, Janendra Pratap Singh alias Mannu arrived at his residence along with Rajkumar Singh and another associate, Golu Singh, and asked him to store a bag containing firearms. Investigators said the weapons were later shifted to a warehouse after Rajkumar Singh's arrest. STF teams subsequently recovered the bag, which allegedly contained a 9 mm pistol, two .32 bore pistols, two .32 bore revolvers, 45 live cartridges and nine empty shells. The murder of Chandranath Rath took place on May 6, 2026, and is now being investigated by the CBI, which suspects the involvement of at least eight people in the conspiracy. The agency also arrested another accused, Vinay Rai alias Pampam of Ghazipur district, from Varanasi on May 1...