Police are investigating after the body of a man was found on a busy motorway.

Emergency services were called to the Pacific Motorway, near Billinudgel — a half-hour drive south of Tweed Heads and the NSW/Queensland border — about 7.15pm on Sunday following reports multiple cars had crashed into an unoccupied motorcycle.

Police were told three cars crashed into the bike before a member of the public located a body, believed to belong to the rider, nearby. He is yet to be identified.

Two drivers were taken to hospital in Byron Bay for mandatory testing while a third was taken to Tweed Valley Hospital to be tested. All three vehicles have been seized for forensic examination.

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Investigations are continuing and a report will be prepared for the coroner. Anyone with information or dashcam footage is urged to contact Crime Stoppers.