Police have uncovered a huge haul of cash, guns and drugs when they intercepted a light plane that flew from Melbourne into Redcliffe Airport on Monday.

Detectives boarded the Piper Aerostar plane after it landed at the suburban airstrip, arresting three men and another 11 following subsequent raids.

They alleged the men were part of an interstate drugs syndicate that police have been investigating for 18 months.

A search of the plane found $1 million in cash and a stash of cannabis with a $3.5 million street value.

Search warrants were then carried out on houses and storage sheds across Brisbane's north where another $1.5 million in cash and a "substantial" amount of cannabis was discovered.

The raids were part of the long running Operation Mugwort, which has seen $8.5 million in cash, weapons, ammunition, cocaine and cannabis seized.

Detectives from Carseldine have worked alongside officers from the Crime and Intelligence Command, forensics and other specialists and the Australian Federal Police during the operation.

Detective Superintendent Tony Fleming said his officers worked tirelessly to target people trafficking drugs.

"People who traffic drugs are profiting from the harm caused to users and people who are crime victims because of illicit drugs," he said.

"Queensland Police are at the frontline of cleaning up the mess every day caused by illicit drugs and this is another proactive operation by police aimed at making our community safer."

The men, aged between 25 and 60, are facing almost 150 charges, including trafficking in dangerous drugs serious organised crime, trafficking in dangerous drugs, possessing dangerous drugs, supply dangerous drugs, receive or possess property obtained from trafficking or supplying, possessing anything used in the commission of crime, contravening an order about information necessary to access information stored electronically, not being endorsed to possess restricted drugs and knowingly dealing with proceeds of crime.

They are expected to appear in the Brisbane Magistrates Court today.

Originally published as $8.5m cash, coke, cannabis and weapons in huge police bust