Wife of slain IPS officer Narendra Kumar Singh, who was crushed under wheels of a tractor-trolley driven by an alleged member of the mining mafia in Madhya Pradesh, has demanded a CBI probe into the incident. Madhurani Tewatia, who is an IAS officer posted in Gwalior and is currently on maternity leave, said merely punishing the driver will not satisfy her. 30-year-old Singh, who was posted as Sub Divisional Officer of Police at Banmore in Morena district was crushed by a tractor-trolley driven by an alleged member of the mining mafia, when he tried to stop the vehicle illegally carrying stones. The distraught father of the 2009-batch IPS officer Keshav Dev alleged that the killing was a “well-planned conspiracy” against his son who did not receive cooperation of local police and authorities. The driver identified as Manoj Gurjar has been arrested and a case registered under section 302 (murder) of the IPC. The Madhya Pradesh government ordered a judicial probe on Friday. The Opposition Congress has also demanded a CBI probe, which has been rejected by the BJP government in the state.