Police say a drug and gun smuggling syndicate operating between Australia and Papua New Guinea was shut down in the operation.

Ten litres of Phenyl-2-Propanone (P2P) was seized, with authorities claiming the chemicals could have been used to create methamphetamines with a street value of $2.5 million.

Police allege the syndicate was importing the P2P from PNG to northern Queensland, via the Torres Strait. Two shipments were tracked in August and September 2014.

It is alleged the syndicate tried to smuggle three guns from Australia to PNG on August 20.

Officers also claim the smugglers are linked to a large cannabis crop in the Atherton Tablelands at Herberton, where 920 cannabis plants were found.

Since May, Australian Federal Police, Queensland Police and the Australian Customs and Border Protection Service have targeted smuggling networks importing items into Queensland from the PNG town of Daru.

Eight people have been charged over the syndicate - five with federal chemical trafficking-related offences and three with state drug offences.

Further arrests have not been ruled out, police said.

Queensland Police Far Northern District drug squad Detective Senior Sergeant Kev Goan said the investigation would have a significant impact on drug traffickers in the region.

"Today's operational closure was the culmination of months of investigation by a committed group of investigators who have now successfully shut down this drug trafficking syndicate," he said.

The maximum penalty for importing drug precursors like P2P is a 25-year prison sentence and an $850,000 fine, police said.