The newly-crowned winner Rueda rode into the back of Dettwiler on the chute between Turn 3 and Turn 4, just after leaving the pit lane.

Dettwiler was riding slowly on the racing line when Rueda rode into the back of the Swiss rider at speed, the Spaniard seemingly unaware of the preceding rider ahead of him.

Rueda qualified third while Dettwiler was set to start from 21st.

The race, which was scheduled for 15 laps, was red-flagged. There was a lengthy delay to proceedings as the riders were attended to by trackside medical staff.

Bikes were taken off the grid and returned to their garages.

Rueda and Dettwiler were reportedly conscious upon being flown by helicopter to a nearby hospital.

Racing could not resume until the helicopter returned to the Sepang circuit, necessitating a new schedule.

The Moto3 race was reduced to 10 laps and scheduled to start at 4:45pm AEDT, one hour and 40 minutes later than initially scheduled.

Moto2 will start at the new time of 6pm AEDT while MotoGP is scheduled for 7:30pm AEDT.

Australia’s Joel Kelso will start the Moto3 race from 11th. Compatriot Jacob Roulstone was ruled out of the weekend due to a broken hand suffered in practice on Friday.