Para-military training camps (if true) with semi-automatic weapons (also if true) is a very serious crime.

Bull shit.

Boy Scouts are a paramilitary organization that have training camps, uniforms, marching, strictly military origins etc. etc.

ie. Paramilitary training camps does not equal crime.

The weapons in question are for sale "on special" "now only $899" at the "NZ's largest firearm dealer"

ie. Possession of the weapons are not a crime.

You are right in saying that maybe they are guilty of something, but nobody has actually said what yet.