The bodies of Sapna Mukherjee (in her sixties) and her husband Dilip Mukherjee (in his seventies) were recovered on July 30 from their residence in Netajinagar.
"Md Hamruj Alam, 38, a resident of Bihar's Katihar has been arrested in connection with the Netajinagar murder and robbery case. He has confessed that he committed the crime. He ran away to Katihar after committing the crime," a senior Kolkata police officer said.
He said that Alam worked as a labourer at the house of the deceased couple. Some of the stolen articles and cash have been recovered from him.
"He will be produced at the local court in Bihar and Kolkata Police will seek transit remand. Further details will be given once we get his custody and are able to further interrogate him," the officer added.
Raising concern over the incident, West Bengal Chief Minister Mamata Banerjee had promised a thorough investigation in the matter. She had instructed police officers to ensure the full safety of the senior citizens.
In another incident, Kolkata police has arrested two persons for carrying more than 3 kg of crude heroin with an estimated value of around Rs 12 crore.
Acting on a tip off, the Special Task Force of Kolkata police on Saturday intercepted a vehicle at Munsi Prem Chand Sarani and recovered 3.208 kg of crude heroin, concealed inside the door of the car.
"Dipak Roy (46) and Kumar Chetri (34), residents of Assam, were arrested for joint possession of narcotic substances. The approximate cost of the narcotics may be between Rs 3-12 crore depending on the concentration," police said.
( With inputs from IANS )