Police divers fail to find missing Qld man

Police divers and sniffer dogs have failed to locate missing Queensland man Sam Thompson or any of his belongings during a search north of Brisbane.

Divers connected to ropes trawled sections of the North Pine River in Murrumba Downs on Thursday, while dogs scoured nearby bushland.

The uncharacteristic disappearance of the 22-year-old on March 7 is being treated as suspicious and has triggered a large-scale investigation.

More than 50 police officers, including homicide detectives, have been tasked with finding the Albion man.

Detective Inspector Tim Trezise said on Wednesday police feared he may be being held captive or dead.

The latest search took place upstream from where Sam's orange Ford Mustang was found the day he went missing.

Police spotted his car at the Deep Water Bend Reserve in Bald Hills, which is located along the North Pine River.

Two days later residents found it abandoned in Wooyung in northern NSW.

Sam's parents Bruce and Debbie and his sister Courtney made an emotional plea on Wednesday for anyone with information to contact police.

"Someone knows where Sam is," Mr Thompson said.

"Please help us find our boy."

Det Insp Trezise said police also wanted to speak to the driver of a white Chrysler 300 who was spotted driving closely behind Sam's vehicle in Bald Hills on the day he went missing.