In Queensland, the possession in public, of a knife or blade of any description can lead to an arrest.
Scouts are not to bring a knife to Jamboree, except for cooking & eating utensils.
Leaders may carry a multi-tool device on their person on the Jamboree site.
Note that Leaders must have a specific reason to carry any form of knife in public - the law requires them to have a reasonable justification (proof of which lies on the person) to carry a knife.