Police have cracked a major drug syndicate.

Police have cracked a major drug syndicate. Photo: WA Police

Police claim to have cracked a major drug syndicate, which they say involve Gypsy Jokers gang members transporting cannabis from South Australia into metropolitan WA.

Three South Australian truck drivers and a 41-year-old Kalgoorlie man with links to the bikie gang have all been charged over the seizure of 29.1 kilograms of cannabis, with a street value of close to $1.5 million.

Serious and organised crime superintendent Charlie Carver said WA, SA and Kalgoorlie police as well as Australian customs launched the joint operation to investigate the drug syndicate's activities.

Police have cracked a major drug syndicate transporting cannabis from South Australia into metropolitan WA, uncovering nearly 30 kilograms of cannabis in three trucks.

Police have cracked a major drug syndicate transporting cannabis from South Australia into metropolitan WA, uncovering nearly 30 kilograms of cannabis in three trucks. Photo: WA Police

The four men were all arrested last night after police tracked three trucks that left Adelaide on Wednesday to a location in Coolgardie, where they met up with the 41-year-old Kalgoorlie man.

Superintendent Carver said the 41-year-old man's car was searched, and 3.2 kilograms of cannabis was allegedly uncovered.

The three trucks were then followed to Southern Cross where they were searched, and officers allege to have found 25.9 kilograms of high-quality cannabis, packed in boxes in vacuum-sealed bags. In addition to this, $25,000 in cash was found.

Superintendent Carver said investigations are continuing into the syndicate's activities in both states, and that they had made a major dent in the gang's drug trade in WA.

"We do believe the drugs were destined for the streets of Perth," he said.

He said police looked into seizing the trucks that had been used to transport the drugs into WA, however the drivers appeared to be the ones solely responsible for the alleged trafficking and the company played no role.

"This is probably one of the biggest seizures for a long time," he said.

"I like to think we have made a dent, we certainly made a dent with the three truck drivers and a 41-year-old [being charged].

"I'm sure the outlaw motorcycle gang members involved will financially suffer in relation to this."

All four men have had their bail refused, and will be appearing in court this month.