Police are holding two suspects after staff discovered the body of a wealthy Arab in his room at the five-star luxury Dorchester hotel.
The death remains "unexplained" but police are not ruling out murder. Paramedics were called to the Mayfair hotel on Friday (1 May).
Scotland Yard said: "The man, in his 40s, was pronounced dead at the scene. Police are in the process of informing next of kin.
"The two men have been arrested in connection with the incident and are in custody at central London police stations."
They have since been released on bail until a date in mid June.
Detectives are examining CCTV footage from the Dorchester as part of their investigations. The Dorchester confirmed an incident had taken place and said it was working with police to help them with their inquiries, according to a Sun on Sunday report.
A spokesperson for the Dorchester, where suites cost around £2,000 a night, said: "With regret we can confirm the death of a guest at the hotel on Friday, May 1.
"We are unable to provide any further details at this time as the matter is in the hands of the police. Our thoughts are with the family and friends of the deceased."
A post-mortem on the man, believed to be an Arab tourist, is being carried out on Sunday.
An eyewitness said: "The hotel was crawling with detectives. It was like a scene out of an Agatha Christie film."
Famous guests who have stayed at the Dorchester include Kim Kardashian, Kanye West, Michael Jackson, Elizabeth Taylor and Charlton Heston.