With the car back home the first step was finding the leak.
I checked under the bonnet and found the power steering fluid reservoir was pretty much empty!
Found the power steering hose and visually checked for leaks (looked for wet patches), found nothing indicating the leak must be under the car. There was a small amount of power steering fluid drips on the floor between the steering wheel and the drivers side wheel.
I refilled the empty power steering fluid reservoir and started the car. Within a minute it had all leaked out!