A five-year-old boy has critical head injuries after falling from a Melbourne carnival ride that may have been operating after hours.
The boy was on the Cha Cha at a carnival in Rye at 5pm on Monday when he was flung from the fast-moving ride.
"Initial inquiries indicate that the ride may have been used by carnival workers and their families after the carnival had closed," WorkSafe Victoria said in a statement on Tuesday.
"WorkSafe was at the scene last night and issued a notice to ensure the scene was not disturbed so investigations could continue today.
"Inquiries will focus on a number of issues, in particular the height requirements for riders, to determine if all safety procedures had been followed."
The boy was airlifted to the Royal Children's Hospital in a critical condition with head and hand injuries.
A parent, who was on the ride with their two children, told Fairfax Media the ride lasted about five minutes before the boy was flung out.
"The attendant announced it was the last ride of the day for the Cha Cha and there appeared to be a number of carnival workers and relatives of workers on the ride," the parent said.
Brittany Clemente was flung from a Cha Cha ride in Lilydale in 2011 and left with ongoing injuries.
"She was yelling out stop, but people didn't know why she was screaming," her mother Silvana Clemente told 3AW on Tuesday.
According to the Wittingslow Amusements website, 44 people can be on the ride at any one time and the minimum height requirement is 130cm.
In 2014, eight-year-old Adelene Leong died after being thrown from a high-speed ride at the Royal Adelaide Show.
Last year four adults died on the Thunder River Rapids ride at Dreamworld on the Gold Coast.© AAP 2017 Image Credit: AAP Image/Julian Smith