Three train passengers were found in an unconscious state in Dibrugarh-Kamakhya Express at Kamakhya station in Guwahati on Monday and one of them died in hospital.
According to the police the three were found in a drugged condition in a compartment of the train around 6.30 am with their money and belongings robbed.
They were immediately admitted to the railway hospital in Guwahati where one of them died in the ICU.
The other two men are in a serious condition, the sources said.
One of them, however, told the police that a fellow passenger had offered them tea and snacks and they fell unconscious after consuming the eatables.
Suspecting the eatables were laced with drugs, he said, the three were also looted of their money and bags containing clothes and other personal belongings.