INVESTIGATORS have encouraged children with information about the Tiahleigh Palmer's movements on the day she disappeared to come forward.
Queensland Police have set up a CrimeStoppers marquee at Marsden State High School, south of Brisbane, where the 12-year-old was last seen alive on October 30.
Fishers in the Pimpama River, in the Gold Coast, found her body on November 5.
Officers also questioned motorists on a bridge that crosses the Pimpama River.
Detective Superintendent Dave Hutchinson said in a press conference officers were concerned schoolchildren were withholding information because they thought they might get in trouble.
"If there's any issue in relation to wagging school or things like that, they're not going to be in trouble," he said.
"We really want them to be honest with us and tell us exactly what occurred."
Police had received 327 calls to CrimeStoppers in relation to the investigation.
Det Supt Hutchinson also said police were appealing to those with dash-cam footage in their vehicles, who were driving near the school on October 30, to come forward.
Police had no murder suspects, and had no further insight into what caused the 12-year-old's death as they were waiting on test results.
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