The milk which caused the deaths of five tribal students of the state Welfare Department-run boarding school — Adivasi Awasiya Vidyalaya — at Bedo block in Ranchi district on November 13 contained endosulphane, a highly poisonous compound found in pesticides and insecticides, the police have said.

The Forensic Science Laboratory (FSL) is expected to submit its report within a couple of days. “Once the report comes out, we will have to find out how the endosulphane was mixed with the milk,” SSP M S Bhatia told The Indian Express.

After the tragedy, Bedo Block Welfare Officer Vishwanath Sahu had lodged an FIR against headmaster Kelment Tigga, warden Jugeshwar Sahu, cooks Jagat alias Soma and Laxman and the supplier of the milk Sarita alias Pratima, holding them responsible for the tragedy.

Tigga is still at large but interrogation of Soma, Laxman and Pratima, who were remanded to judicial custody on November 18, revealed that the milk was supplied by Pratima in the morning. “A number of students had consumed it then without any problems,” Pratima told The Indian Express. But the 43 students and Sahu, who drank it in the evening, became its victims. Five of them died and 39 others including Sahu were hospitalised within hours of its consumption.