Following the deaths, officials from the Mumbai Police, forensic teams and the Food and Drug Administration visited the family’s house.
They collected samples of all food items consumed during the gathering.
These included chicken pulao, watermelon, drinking water and other food items.
The samples were sent to the Forensic Science Laboratory for detailed testing.
Police have also recorded statements from relatives, neighbours and others connected to the family.
The JJ Marg police station is leading the investigation.
Questions still remain
While the discovery of zinc phosphide has ruled out bacterial food poisoning, several questions still remain unanswered.
Investigators are trying to find out how the poison entered the family’s food and whether it was mixed accidentally or deliberately.
Officials said the final forensic science laboratory report will provide clearer answers.
The case has shocked residents in the area, especially because the family had appeared normal during the gathering earlier that evening.
Police say the investigation is still ongoing and more details are expected after the final reports are received.
(With inputs from agencies)