A female motorbike rider has died at the scene of a horrific crash with a 4WD on Monday.

The 69-year-old woman was treated by NSW ambulance paramedics that rushed to May Farm Rd in the small village town of Brownlow Hill, about an hour southwest of Sydney, at 2.30pm.

Sadly, she could not be saved.

The 4WD driver, a 74-year-old woman, was taken to Campbelltown Hospital for mandatory testing.

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Police are at the scene and have launched an investigation into the cause of the fatal collision.

Anyone with information should contact Crime Stoppers.