The accused, Nagesh S, allegedly called up the businessman on November 24 and demanded Rs 1.5 crore by threatening him.
A case was registered under sections 385 (putting person in fear of injury in order to commit extortion) and 506 (criminal intimidation) of the IPC against Nagesh, a Saroor Nagar police station official said.
"A police team arrested Nagesh in a decoy operation when he came to pick up cash bag," he added.
The slain criminal had formed a gang and was allegedly indulged in land grabbings, extortion, kidnappings etc, many of which were not reported to the police due to fear of reprisal.