Investigators probing the armed robbery at the residence of a cardiologist in Anna Nagar on Tuesday suspect the hand of the domestic help and her husband in the incident.

The police are scrutinising CCTV footage from a lodge in Arumbakkam, which shows the male suspect and his accomplices, all from Kolkata, leaving the premises with what appears to be the stolen items. The robbery was allegedly committed at gunpoint at the bungalow of Dr. R. Anandan in Q Block. His wife Shanti and elderly mother Andalammal were at home with their domestic help Meena, when a gang of five men entered the compound.

Two of them — Meena’s husband Imran and his accomplice, Shabir — entered the bungalow and stole 119 sovereigns of gold jewellery, a diamond ring worth Rs. 5 lakh and nearly Rs. 4 lakh in cash.

“The duo tied up the three women including the maid. On questioning the maid we found she had planned the robbery along with Imran and Shabir,” said an investigating officer. The maid’s real name was Hakitha Begam and she was working on the guise of an unmarried woman at the doctor’s residence for the last two years, he added.

On inspecting Hakitha’s mobile phone, the police found photographs of Imran, and her call records indicated she had called him before the robbery, an officer said. Investigators then traced Imran’s location to the lodge. “The gang came to the lodge after the robbery, changed clothes and swiftly left the premises. They could have fled the city by train, possibly to Kolkata. Two teams have left for West Bengal,” the officer said.