Officers were called to concern for safety between junction eight and junction nine near Gatwick at around 6am today (September 10).
South East Coast Ambulance Service also attended and the pedestrian, a woman, was pronounced dead on the carriageway.
Her next of kin have been informed.
Traffic was held in both directions but the northbound carriageway was reopened just after 8am.
An investigation into the circumstances of her death is underway.
No arrests have been made.
Lanes three and four of the southbound carriageway were opened at 2pm.
Lanes one and two remain closed and are expected to remain so for several hours.
Surrey Police is making a mandatory referral to the Independent Office for Police Conduct (IOPC) due to police contact with the deceased in the days prior to the incident.
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This is a breaking news story. More to follow.
