Jaipur, July 2: A drunk young man at the wheel of a speeding BMW said to be owned by his lawmaker father rammed into an autorickshaw early today, killing three persons in the three-wheeler that sources said was tossed into the air under the impact.

The Rs 50-lakh luxury sedan, whose speed a police officer said must have been somewhere between 100-120kmph, then hit a stationary police van, injuring several policemen.

Police have arrested Siddharth Maharia, 24, son of Rajasthan Independent MLA Nandkishore Maharia, under the penal code's Section 304 for culpable homicide not amounting to murder.

Deputy commissioner (south), Jaipur, Manish Agarwal said an on-the-spot breathalyser test on Siddharth read 152mg, far above the permissible limit of 30mg per 100ml of blood.

An officer investigating the case said they were "not sure" if Maharia, MLA from Fatehpur, Sikar, who mentioned assets valued over Rs 9 crore in his 2008 election affidavit, owned the car. "We are yet to get the registration papers," said Kamal Nayan, SHO, traffic (south).

Police sources said the BMW hit the auto around 2am on one of Jaipur's main thoroughfares, flinging the three-wheeler into the air and killing the driver and two passengers on the spot. One passenger escaped unhurt. The speeding car then hit the police van, injuring four policemen, one of them seriously.

Asked about the car's speed, deputy commissioner Agarwal said: "The actual speed can be ascertained only after the CCTV footage is analysed but it must have been somewhere between 100-120km per hour."

The 520d sedan was also badly damaged in the accident.