The threat posed by bikie gangs has been compared to terrorism by the Australian Federal Police.
AFP Commissioner Reece Kershaw warns Australians who use drugs are bankrolling murders and enabling violence in their communities.
"A patched member's ideology is unadulterated greed through the relentless trafficking of illicit drugs," Mr Kershaw told the National Press Club on Wednesday.
"That ideology has killed more Australians than terrorism. A terrorist attack pierces the heart of our democracy, shatters our confidence and fuels fear."
He argues decriminalising illicit drugs will provide "a beacon for those syndicates and cartels that makes Australia a less safe and less fair society".
Mr Kershaw says 289 people have so far been charged with 724 offences, mostly drug-related, from an underworld sting dubbed Operation Ironside.
About a third of people arrested were either outlaw motorcycle gang members, mostly Comancheros, or people working for them.
One gang plotted to kill a family of five because the bikies couldn't find a relative who had failed to pay a drug debt.
Authorities also uncovered a Comanchero plan to murder an associate with a machine gun at a cafe.
