An anonymous tip led to police breaking up a dial-a-dope ring, with nine people charged with trafficking offenses and arrest warrants being issued for another four.

The 18-month-long investigation by North Vancouver RCMP began in September 2007, when police received a call through Crime Stoppers about the dial-a-dope ring which police say was operating under the guise of a medical marijuana aid group called "The Compassion Association".

The group was allegedly headed by 31-year-old Jason Thon of Vancouver. Search warrants were executed both on Thon's residence in Vancouver and a storage locker where almost six kilograms of marijuana were seized, said police in a statement.

Along with Thon, the remaining 12 received a total 41 charges.

Those arrested are Kevin Moriarity, 39, Debra McDonald-Myers, 32,  Laura Marsden, 27, Katie Kreter, 30, Angela Gentili, 30, Sarah Albo, 28, Jessica Wilson, 28, and Katherine Wedermire, 27. All are from Vancouver, apart from Kreter, who is from White Rock.

Warrants have been issued for Granger Vowel, 28,  Kathleen Seguin, 35,  Douglas Rutka, 28, and Lauren Marsden, 27. All are from Vancouver. 

Police say Compassion Clubs are illegal in Canada, but added there are legal ways to obtain medical marijuana for those who are prescribed it through the federal government.

Please visit the Health Canada website for more information regarding medical marijuana.