Authorities in Agra, India, have said preliminary enquiries suggest "a case of overdose of drugs".
James Oliver, 28, and Alexandra Nichola Gaskel, 24, were found dead at the Hotel Maya in Agra.
They were both identified by their passports.
Hotel staff investigated the rooms when they failed to answer the door.
The pair had been in India since July 11 and had travelled around the country throughout the summer.
They arrived in Agra on October 18 and had only been at Hotel Maya for one night.
A senior superintendent in the city said: "It appears the two were dead on Monday night itself, as the food they had ordered had not been eaten".
The British High Commission in India were informed this morning.
Police are awaiting a post-mortem before announcing the cause of death, but admitted finding "stress-relieving drugs" and sleeping pills in the room.
