Police are attempting to establish how a pedestrian who died in an accident on the M4 came to be walking on the motorway.
The crash involved a lorry and happened on the eastbound carriageway between junctions 11 and 10 near Reading, Berkshire, just before 3am on Tuesday.
A Thames Valley Police spokesman said: "Sadly, the pedestrian died at the scene. The lorry driver is uninjured but is believed to have suffered from shock."
Inspector Andy Storey said: "We would appeal to anyone who was driving on either the east or westbound carriageways of the M4 near Junction 11 at around 2.50am to contact police as we are trying to determine the circumstances which led to a pedestrian being on the motorway.
"In addition there are ongoing enquiries to identify the pedestrian at this time."
The road was closed for several hours while emergency services and the highways authority dealt with the incident.