Police are investigating an overnight incident in which a woman was hit by a car at a caravan park.

Officers were called to the Kingsway Caravan Park in Perth's north around 11:00.

It's understood a female visitor to the park struck the centre's manager with her car.

Witnesses who saw the incident apprehended the woman and held her until police arrived.

The 59-year-old victim remains in a critical condition in hospital.

A 45-year-old woman is helping police with their investigation.