Queensland police have recommended no criminal charges be laid over the Dreamworld ride tragedy in which a New Zealander died last year.
New Zealand woman Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozbeh Araghi, all from Canberra, were killed on the Thunder River Rapids ride, when their raft collided with another near a large conveyor belt at the end of the ride.
The police report into the incident has been delivered to the coroner, ahead of a likely inquest next year.
The investigation looked at the role of park employees, including the young first-time operator of the ride.
The 30-year-old ride has been demolished since the accident.
No criminal charges have been laid as yet but the park's employees and its owners could still face prosecution by the Queensland government.
In August, the state government began the process of making "industrial manslaughter" an offence, after an independent review into the tragedy.