The victim, named as Blue Stevens by the Mirror, died outside the five-star Park Tower Hotel and Casino in Seville Street just after 9.30pm yesterday (July 9).
Police are aware of reports that the man died after being the victim of a robbery.
Those closest to the victim have been told and are now being supported by specialist officers.
A Japanese tourist said they saw the attack, and told MailOnline: “A woman who looked like she was with the injured man was screaming ‘oh my god’ again and again.
“She was very very agitated. It was horrible for us to see.
“We can’t get the incident out of our heads. We didn’t sleep last night.”
A worker at a luxury hotel told MailOnline: “I saw the man lying out on the pavement, a woman was supporting him and crying.
“There was a lot of blood. He was wearing a white or cream coloured t-shirt.
“He was unconscious.”
There have been no arrests but an investigation is underway.
A forensics tent visible outside the central London hotel behind a police cordon in the busy area.
Superintendent Owen Renowden, who leads policing in Kensington and Chelsea, said: “Our thoughts are with the victim’s loved ones following the shocking events that took place last night.
“Detectives from the Specialist Crime Command, supported by local officers, are working at pace to establish the circumstances of what happened.
“We are aware of reports that this incident was a robbery.
“Although this is an active line of enquiry, we are keeping an open mind about all possible motives and the exact circumstances are still to be determined.
“We understand the impact this incident will have on the local community and you will see extra officers in the area to help answer any questions or concerns.”
Please call police on 101 referencing CAD 8521/09JUL if you were a witness or have any information which might help.
You can also contact Crimestoppers anonymously on 0800 555 111 or on its website.
