Body of boy, 9, found after dad ran into him on high-speed jet-ski

The body of a nine-year-old boy who went missing after a jet ski crash in western Queensland has been found by water police.

The boy disappeared after the jet ski his father and six-year-old brother were riding hit him at high speed while he was standing on the bank of Lake Moondarra, near Mt Isa, Saturday morning.

Queensland Police confirmed they found the boy's body about 6am Sunday, after resuming a search and rescue mission which began late Saturday but paused at dusk.

The jet ski was being driven by the boy's 34-year-old father, and both he and another son were thrown onto the bank after the impact.

Both are believed to be in a serious but stable condition. The six-year-old suffered suspected spinal and leg injuries, and the father is being treated for with head and spinal injuries.

"We believe the water craft was being ridden at very high speed, the exact circumstances of how it collided with the bank and struck the boy we don't know," Queensland Police Superintendent Kev Guteridge told the ABC on Saturday.

"For some reason, the jet ski has collided with the bank, which also resulted in the young nine-year-old boy being struck by the jet ski at high speed," he said.

"Tragically as a result of that the boy we believe was thrown in the water.

“This is one of those tragic events where a family fun day turns tragic in a split second.”

Police and the State Emergency Service used a helicopter, ground and swift water rescue crews to search for the missing boy, and divers were flown from Brisbane to assist.

Police are investigating the cause of the crash.