A section of the M1 is closed in both directions today after the body of a man was discovered on the carriageway, South Yorkshire police said.
The motorway was shut down in the Barnsley area, between junctions 37 and 36, after a lorry driver found the body at around 4am this morning.
A spokesman for South Yorkshire police said: "We believe a male has possibly fallen from a bridge over the motorway. It would appear he has been struck by a number of vehicles."
He added that it was not clear whether the man had jumped, fallen, or been pushed from the bridge. Forensic experts are currently examining the area.
The closure has caused big traffic delays between Sheffield and Leeds, one of the busiest stretches of the motorway.
Police say the M1 will probably remain closed until midday and are urging drivers to avoid the area.