The police, however, have asked the three industrialists in question to submit details of their passports and information on their recent visits abroad, including middle-eastern countries like Saudi Arabia, said sources. The close relatives and business partners of these industrialists have also been asked to furnish similar information. “We want to see whether the businessmen were being tracked since their visit to foreign countries. The callers were fully aware of the financial status and other details, including information about their families,” said a police officer.

Deputy Commissioner of the Detective Department, Damayanti Sen, however, said: “I have nothing to say in the matter. The investigation is on.”

Additional security has also been provided to the three businessmen and their relatives.