The investigation, dubbed "Operation Beech", has led to the arrest of 12 people with alleged links to the Mexican drug cartel.
WA Police Commissioner Col Blanch said the operation spanned six weeks and involved intensive surveillance and resources.
"This was an opportunity to catch the syndicate - the group of people that were capable of receiving it, landing it and then distributing it across Australia," Commissioner Blanch said.
"The message from the WA Police Force is unchanged … we will come after you, regardless of where you live on this earth."