Passengers were stunned on Sunday when a train arrived at a crowded platform with a body plastered to the front end of the train.
Police say the man was a cyclist and aren't sure if he died by accident or if he committed suicide.
The train was traveling from Paris and passing through a village when it reportedly hit the man, which took place out of the driver's view.
His corpse wasn't discovered until the train, which can travel at 200mph, stopped about 25 miles later at the next station in Mulhouse.
The man is said to be 48-years-old and from a north-eastern region of France.
Some witnesses have received counseling for shock and emotional trauma while police carry out an investigation.