Officers were called to the five-star venue in Mayfair on Friday evening following reports that a man was unresponsive in one of the rooms.
The coroner has ordered further toxicology tests, which could test for a drug overdose. Tests may take around eight weeks.
Police are treating the sudden death as unexplained.
The man, in his 40s, reportedly an Arab tourist, was pronounced dead at the hotel at 17:30 BST on Friday.
The Metropolitan Police said two men, known to the dead man, were arrested in connection with the death and bailed to a date in June.
Next of kin have been informed but formal identification has not taken place, the force said.
Post-mortem tests on a man found dead at London's Dorchester hotel were "inconclusive", police have said.