After the train had arrived here from Lalgarh in Rajasthan, cleaners spotted a plastic drum inside a bag near the bathroom of S-7 coach, RPF sources said here.
On opening the drum, a decomposed body of a young girl was found.
The body has been sent for postmortem.
Railway authorities have ordered an enquiry and efforts are on to identify the passengers, who had boarded the coach and left the bag, the sources added.