a BHG can do it, and then again, may not...
firstly - a BHG has the right to ask a trader who carrys contraband to stop. - but in contrast to a real police/navy guy, the trader doesn t need to stop. ( so its no lawbreaking not to stop ) -
about the reasons for a BHG to do it...
a BHG does not get rich by stopping a trader and asking him to drop the stuff. - unless he has a contract about it. but! - a BHG may... if he catches a smuggler red handed ask the smuggler to drop the stuff and tractor it in to sell it himself ( in the end its only evidence ) - but should do so at a nearby police base. ( so, no hauling the stuff to the highest bidder )
a BHG should not do it, when there is police around, cause thats the polices job.- if he forces the trader to drop his stuff ( or even destroys the trader ) he should make sure the police doesn t see it, cause its a criminal act. ( the police has fines for smugglers, - and only executes a death penalty, when the trader does not comply, the BHG has no authority to rightfully kill people....... but if there is no law enforcement around... no one will know )
in the end, what will the smuggler do ? run to the police and complain about a BHG taking his cardamine? - so its a grey area of justice that the BHG can exploit.