Chennai: Police are investigating the mysterious death of four persons from the same family after developing health complications at their residence in Kondithope on Sunday.

Preliminary investigation suggested food poisoning to be the cause of deaths, which occurred in a span of six hours on Monday. The deceased were Nandakumar (56), his wife, Kalaivani (52), their son, N.Purushothaman (30) and Kalaivani’s aunt, Lalithaa (65).

The deceased lived as a joint family in a house on Vengu Street, Kondithope. Nandakumar’s mother Janaki (72) and his younger brother; Sundaramoorthy - his family and Kalaivani’s mother Sivakami (70) and aunt Lalithaa (65) also lived in the same house, according to neighbours. Nandakumar was into wholesale cosmetics business.

Investigations revealed that complications arose on Sunday afternoon when Nandakumar initially complained of dysentery after which he was treated at a local clinic. “Over the course of the day, all family members except Sundaramoorthy and Janaki developed similar symptoms,” an investigating officer said. The family had idli and dosa as breakfast on Sunday made from a week-old batter which they also used on Saturday night, police said.

On early Monday morning, sexagenarian Lalithaa first raised an alarm and died within a few hours. The others were rushed to a private multi specialty hospital on Mint Street, a few metres from their home where they were treated. Nandakumar and Kalaivani died

without responding to treatment around 7 a.m, police said. A few hours later, their son, Purushothaman too died after which the four bodies were moved to Government Stanley Hospital for post mortem.

The older women, Janaki (72) and Sivakami (70), mothers of the deceased couple were still under treatment, police said. “Doctors have suggested the possibility of food poisoning. We have secured the batter stored in the refrigerator and sent it for tests. However, what led to food poisoning can be ascertained only after post mortem on Tuesday morning,” said a senior police officer. Seven Wells Police have registered a case and are investigating.