The deceased have been identified as Maya (55) and her daughter Nishu (34), both residents of Bulandshahr's Yakubpur village, they said.
A case has been registered at the Government Railway Police (GRP) police station and investigation is underway, said a senior police officer.
The bodies were found in two bogies of Mahananda Express plying between Delhi and Alipurduar (WB). The train had been stationed at Shahdara station due to disrupted rail traffic caused by floods in Bihar.
"The bodies have been sent for postmortem. The exact cause of death will be determined through autopsy report," said the officer.
The identity of the mother-daughter duo was ascertained through a paper slip found from the victims. The address of Yakubur village in Bulandshahar was scribbled on it, police said.
Maya belonged to Mathura and her daughter Nishu was married to one Pushpendra of Yakubpur in Bulandshhar. The mother, a widow, lived with the family of her son-in-law in Yakubpur, they said.
Police enquiry also revealed that Maya owned land in Mathura and her brother-in-law allegedly wanted to grab the land.
"Teams have been formed to probe the deaths from all possible angles, including property and family dispute, dowry, as well as sexual assault. The CCTV footage is also been scanned," added the officer.
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