A man's body found on the M1 in Northamptonshire appears to have been run over several times, police have said.
The victim, identified as 46-year-old Ashley Hayes from Shepherd's Bush in west London, was discovered by a motorist shortly after 2am on Tuesday on the northbound carriageway near Daventry.
Police believe that Mr Hayes, who was identified via his fingerprints, could have hidden himself in a lorry.
"This may have been an accident or something more serious," said Detective Sergeant Tony Hopkins.
DS Hopkins added that inquiries had suggested Mr Hayes could have been in the Toddington Services area in Bedfordshire at 1.30am.
The officer said: "He may have been given a lift from there, or may have hidden himself in a lorry, to enable him to get to where we discovered him."
Earlier, DS Hopkins said Mr Hayes' injuries were "catastrophic".
He said: "He could have been on a vehicle, he could have tried to exit from a vehicle, been forced to get from that vehicle."
Officers do not believe Mr Hayes jumped off a footbridge.
"He appears to have come into contact with several vehicles on the M1. We can only describe the scene and injuries as catastrophic," DS Hopkins added.
"It may be a fail to stop collision," he said, "or it may be that a motorist believed they hit an animal.
"There is no nearby bridge or obvious footpath that would indicate where he may have come from.
"The particular stretch of road is unlit and there are roadworks restricting the speed limit. People wouldn't expect there to be a pedestrian in the road.
"It may be an innocent accident or something more serious."
He continued: "There will be lorry drivers and other motorists who may have driven this stretch of road and some of them may have dashcam footage.
"We would urge anyone with any information to come forward."
:: Witnesses or anyone with information should call police on 101 or Crimestoppers on 0800 555 111.