New Delhi, Mar 15 (PTI): The Central Bureau of Investigation (CBI) on Thursday began the probe into the killing of young Indian Police Service officer Narendra Kumar Singh allegedly by the sand mafia in Madhya Pradesh after it registered a case and dispatched a team of experts to the murder spot.

After receiving a notification from the Centre, CBI registered a case against unknown persons, agency sources said. The Centre issued the notification on the request of Madhya Pradesh Chief Minister Shivraj Singh Chouhan, the sources added.

Soon after registering a case, a team of CBI officials and experts of Central Forensic Science Laboratory was dispatched to the crime site where the 30-year-old officer was run over by a tractor purportedly owned by sand mafia in Morena district.

Chauhan had ordered a judicial inquiry into the incident and also recommended a CBI probe. Kumar's wife, Madhu Rani Teotia, an IAS officer, had demanded a CBI probe.

Kumar, a 2009-batch officer, was posted at Banmore in Morena district as Sub Divisional Officer of Police a month ago and had taken on the mining mafia by seizing number of vehicles engaged in illegal quarrying.

The incident occurred on Holi, March 8, when Kumar, who was out on patrolling duty in his official jeep, saw the trolley loaded with stones. He signalled the driver to stop but the driver ignored his signal. So he followed the vehicle, cut in and stood in front of the vehicle after getting off his jeep.

But the tractor driver drove on and knocked him down, crushing him to death. The driver was arrested.