Kolkata, Jun 7 (PTI) Police suspect that the Gujarati couple, found murdered at their residence in south Kolkata"s Bhabanipur, was killed by someone close to them, a senior officer said on Tuesday.The killings might have links to the share market, in which the couple had significant investments, he said."Circumstantial evidence indicates that those who came to their house were known to them and the woman might have opened the door. There is a very deep injury on the shoulder of the woman whose body was found lying near the entrance," the officer of the Kolkata Police said.Police are also trying to find if the couple had taken any loan from anyone to invest in the stock market, which might have a connection to the deaths, he said.Police have recovered the shell of a bullet from one of the rooms.The mobile phones of the couple were seized as detectives are checking their call logs, the officer said.The bodies were found on Monday evening, sparking tension in the area which is considered to be a high-security zone because of its proximity to Chief Minister Mamata Banerjee"s residence.The couple -- identified as businessman Ashok Shah and his wife Rashmita Shah -- were found dead at their flat on 73/A Harish Mukherjee Road. The couple is survived by three daughters. PTI SCH SOM SOM