Police were called to Sipson Lane, Harlington at 06:16hrs on Sunday, 31 October after a passing motorist noticed a person at the side of the road.
Officers attended with London Ambulance Service paramedics. They found a man who was believed to be in cardiac arrest.
Despite the efforts of the emergency services, he was pronounced dead at the scene at 07:00hrs.
His death is being treated as suspicious and a murder investigation has been launched.
A post mortem examination will take place in due course.
While formal identification has yet to take place, officers are confident the deceased is 28-year-old Mohamed Muhiyidin of Southall, Ealing.
His next of kin have been informed and are being supported by specialist officers.
Detective Inspector Melanie Pressley, of the Met’s Specialist Crime Command, said: “We do not yet know how Mohamed came to be lying injured at the side of the road this morning, but there will be people out there who do know.
“I would appeal to anyone with information about this incident to come forward. I would also ask anyone who knew Mohamed and may know why someone would wish to do him harm, to speak to us.
“In addition, I would appeal to anyone who drove along Sipson Lane on Saturday or in the early hours of Sunday morning to check any dash cam footage they may have to see if it captured anything unusual.
“A family is grieving after hearing the terrible news that their loved one has been murdered. We will do everything we can to find out who is responsible, but we need the public’s help.”
Anyone with information should call 101, giving the reference 2365/31OCT.
Information can also be provided to Crimestoppers, anonymously, by calling 0800 555 111 or by visiting www.crimestoppers-uk.org
