Police have seized more than $5.4 million worth of cannabis from a Southern Downs property in Queensland as part of an ongoing drug operation.

Key points: Police found 1,825 cannabis plants and about 140 kilograms of dried cannabis at a property

Police found 1,825 cannabis plants and about 140 kilograms of dried cannabis at a property Three of those charged were Vietnamese nationals who were in Australia illegally

Three of those charged were Vietnamese nationals who were in Australia illegally Seven people have been charged overall and have appeared in court on a number of serious drug offences

Authorities searched the site on Kessler Road in the Talgai district, near Warwick, on Tuesday and found 1,825 cannabis plants and about 140 kilograms of dried cannabis.

Acting Inspector Jamie Deacon said the investigation had cracked a significant drug ring operating in the region.

"The set-up was very commercial-grade and sophisticated, which included irrigation and hydroponics set-ups," Acting Inspector Deacon said.

"This is a significant step towards dismantling and certainly the disruption of organised crime within Queensland."

Operation Papa Cider included Australian Border Force (ABF) officials, who found three of those charged were Vietnamese nationals who were in the country illegally.

Two people were found to be unlawful non-citizens and one was in breach of a bridging visa.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 59 seconds 59 s Detectives carried out search warrants and arrests during the cannabis farm bust

Detective Superintendent Jon Wacker of the Drug and Serious Crime Group said it was a concern foreign nationals were involved in the cannabis production scheme.

"Operation Papa Cider is about more than just the production and trafficking of dangerous drugs on our streets," he said.

"We have been working closely with our partners at the ABF and the Australian Federal Police to target the exploitation of unlawful non-citizens for the sole purpose of producing and manufacturing these drugs.

"Our approach is to target the high-level distributor who is reaping lucrative benefits from an illicit drug, all the while removing themselves from the crime and reinvesting the profits into other illicit activities directly impacting on our community."

Seven people charged with drug offences

Four people, aged in their mid- to late-40s, were arrested after vehicles were intercepted at Leyburn after the raid.

Overall seven people have been charged over the sting and have appeared in the Warwick Magistrates Court on a number of serious drug offences.

Acting Inspector Deacon said an earlier bust where 250 kilograms of cannabis worth more than $1.5 million was found during a routine traffic intercept on the Warrego Highway at Minden in March, had led to this week's raids.

"Investigations stemming from intercept have led us to this crop at Leyburn," he said.

The ongoing operation has already resulted in several arrests, including the arrest of two people and the seizure of $1,350,000 worth of cannabis seized from grow houses in Moorooka, Upper Mount Gravatt and Annerley in June last year.