Metropolitan Police were called to Richmond Bridge, Richmond, at about 4am on Saturday.

Police found the victim who had suffered serious injuries in the incident, which had been ‘watched by a number of people’.

Officers administered CPR before paramedics took over and transported the man to hospital, where he died later that morning.

His next of kin have been informed and are being supported by specialist officers.

There have been no arrests over the alleged murder, and a post-mortem examination is yet to be performed.

Detective chief inspector Katherine Goodwin, who is leading the investigation, said: ‘We believe a number of people watched the incident unfold and some onlookers may have recorded footage on their mobile phones.

‘Anyone who has yet to speak to us is urged to come forward immediately.

‘My team are working to provide the deceased man’s family with answers and the public could have valuable information that will help our investigation.’

Richmond policing lead chief superintendent Lis Chapple confirmed officers will remain at the scene and in the area to speak to residents about the incident.

‘My thoughts are with the man who died and his family,’ she said.

‘We will do everything we can to support our colleagues in specialist crime as they work to establish what has happened here.’