New Zealand jockey Alysha Collett is in a Singapore hospital following a fall during a race at Kranji.

The 24-year-old fractured a lower backbone and her right heel when she fell on Sunday after her mount Riding Drone stumbled.

The two were at the 250m mark of the 1000m- race when Riding Drone was in restricted room between horses.

Collett, the younger sister of top 10 Sydney jockey Jason Collett, told the Singapore Turf Club the fall happened in a split second.

"It happened so quickly - I felt like I was being catapulted," she said.

Her injuries were "very painful" and she couldn't move much, she said, adding her first worry was being trampled and injured further.

An MRI scan on Collett's brain was clear but a decision about surgery will be made after further scans on her spine, she said.

Riding Drone was uninjured in the tumble.

A stewards inquiry will be held into the fall.