The architect received the call on June 27 while he was at his office in suburban Borivali by a person, who identified himself as Ravi Pujari, and asked him to shell out Rs five crore, a Thane Rural Police official said.
According to complaint lodged by the architect, whose name has been withheld, he also received a few more calls from different numbers demanding the same amount.
A case was yesterday registered under IPC sections 384 (extortion) and 507 (criminal intimidation by an anonymous communication).