"Siddhartha is suspected to have jumped into the Nethravathi river near Mangaluru from the bridge though his body has not been traced so far despite massive search operation," Mangaluru Police Commissioner Sandeep Patil told reporters.

Earlier, Siddhartha's driver Basavaraj Patil filed a complaint in a Mangaluru police station that his boss was missing from the bridge over the river where he got down from his car and wanted to take a walk.

"Siddhartha got down from the car on the bridge across the river and asked him (Patil) to wait at the other end of it as he wanted to walk for a while but did not turn up even an hour later," said Patil in his complaint.

Police suspect Siddhartha would have jumped into the flowing river from the bridge as the driver found him missing in the area since then.

Siddhartha, 60, is the eldest son-in-law of BJP's senior leader and state's former Chief Minister S.M. Krishna.

Siddhartha had sold his entire 20 per cent equity stake in the city-based software major Mindtree Ltd to the Mumbai-based Larsen & Toubro (L&T) for Rs 3,300 crore at Rs 980 per share of Rs 10 face value on March 18.