More than 300 extra staff will be recruited to address failings in Western Australia's St John Ambulance service, the state government says.

WA Health Minister Kim Hames has announced 309 new paramedics and officers will be brought in over the next four years, following an independent review of St John Ambulance operations.

t John, a nongovernmental organisation, is active nationwide but it runs the ambulance services in WA and the Northern Territory.

he review was sparked by a damning ABC Four Corners program two years ago that revealed shortcomings and a lack of resources and skills in the WA service that were linked to avoidable deaths.

It highlighted failings in the ambulance service's call centre that resulted in urgent cases not being fast-tracked.