Jesse Bitz, 36, and five other club members were charged last year under the year-old provincial Safer Communities and Neighborhoods Act for wearing the club's trademark designs on their vests in a bar, the Saskatoon StarPhoenix reported.
Monday, Bitz's lawyer argued in a Saskatoon court the law was unconstitutional as it encroached on the federal rights of freedom of expression.
In turn, prosecutor Graeme Mitchell said the province was within its rights to define public safety in provincially licensed establishments, the report said.
The law was created to counter gangs involved with drug trafficking, prostitution, racist groups and child exploitation, provincial investigator Dwayne Gulka testified.
The challenge was the first of its kind and the fate of the other five bikers charged hinges on the outcome of the ongoing hearing, the newspaper said.