The water given to the three Unnao girls, which led to the death of two of them, had been mixed with Sulfosulfuron, a herbicide, police said on Thursday. The report of the chemical analysis of the viscera of the two girls found dead on February 17 night, released by the Forensic Science laboratory (FSL), Lucknow, has revealed the presence of Sulfosulfuron in their vital organs.

Unnao Superintendent of Police (SP) Anand Kulkarni said the accused used Sulfosulfuron, which is an odourless herbicide, to poison the water. "It was due to this that the girls did not realise they were being poisoned. Besides, the water of the hand-pump from which the bottle was filled is poor in taste," he added.