A builder discovered the decomposing body in Longford, West Drayton near Heathrow on Wednesday.

The site is close to the Harmondsworth detention centre, which houses hundreds of asylum seekers.

Initially it was thought the body had fallen from a plane.

But a post-mortem examination has since established the cause of death as multiple stab wounds.

Victim 'known'

Police have started a murder investigation.

The dead man was an eastern European, who police believe was a Kosovan asylum seeker aged between 19 and 22 years old.

The body has not been formally identified, but police believe they know the victim and say they are keeping an open mind as to why he was killed.

Stanwell Moor Road has been re-opened, but the site where the body was found is still cordoned off while forensic officers examine it further.