Officers were called to the scene on the M6 southbound between junction 27 and 26, near Wigan, at just before 1.30am on the morning of Friday August 16.
The motorway was closed well into the following afternoon as police and paramedics went about their work.
A Greater Manchester Police spokesperson said: “At around 1.25am this morning, Friday August 16 2024, we were called to the junction 27 of the M6 for a concern for welfare of a female.
We attended the scene and sadly discovered the body of the female.
The M6 southbound between junction 27 and 26 is closed while officers continue with their investigations.
“Significant delays are to be expected in the area for the immediate future.
“Thank you for your patience at this time.
Closure was maintained well into Friday, as officers had reported earlier in the morning that they had been summoned to reports of someone falling off a bridge.
Throughout the day, there were severe delays and traffic diversions.
Anybody with information about the incident, such footage from a dashcam, CCTV, or cell phone, is urged to call 101 and provide log number 171 of August 16, 2024, according to the officers.
A little after 2:00 pm, the road reopened.
