"Search is on since morning. Siddhartha is suspected to have jumped into the river from a bridge on way to Mangaluru from Ullal on Monday night," Mangaluru Police Commissioner Sandeep Patil told reporters on Tuesday.
"About 200 people, including policemen, coast guards, divers and fishermen are engaged in the search around the area in the river where Siddhartha is suspected to have jumped into," Dakshina Kannada Deputy Commissioner Sasikanth Senthil said after visiting the spot.
Earlier, Siddhartha's driver Basavaraj Patil filed a complaint at a local police station that his boss had gone missing after he got down at the bridge from the car and started walking while talking on mobile.
"Siddhartha got down from the car on the side of the bridge and asked me to wait for him at the other end of it, as he wanted to walk for a while. But he did not turn up even after an hour," said the driver in his complaint filed in Kannada.
Siddhartha, 60, is the eldest son-in-law of S.M. Krishna, senior Bharatiya Janata Party (BJP) leader and former External Affairs Minister in the UPA-II government (2009-2012). Krishna was also Karnataka's Chief Minister between 1999 and 2004.
Siddhartha had on March 18 sold his entire 20 per cent stake in the city-based software major Mindtree to the Mumbai-based Larsen & Toubro (L&T) for Rs 3,300 crore at Rs 980 per share. He wanted to raise funds to reduce his company's mounting debts.
"Sir (Siddhartha) and I left in a car from Bengaluru on Monday afternoon for Sakaleshpur near Hassan, where he has a house near one of his coffee estates. On reaching there by evening, he told me to drive to Mangaluru on National Highway 66. When I drove onto the bridge, he asked me to stop the car and got down, saying he would walk and get into the car at the end of the bridge on the other side," the driver recounted.
When Siddhartha didn't reach the other side of the bridge, the driver went in search of him but he was nowhere to be found. "I filed the complaint with the local police past midnight on his family's advice, when I told them how Siddhartha suddenly went missing," Patil told the police.
The port city of Mangaluru is about 350km west of Bengaluru.
( With inputs from IANS )