Every person in an aircraft shall obey all lawful commands which the commander of that aircraft may give for the purpose of securing the safety of the aircraft and of persons or property carried therein, or the safety, efficiency or regularity of air navigation.
Nowhere in the ANO does it state that upon parking -
command of the aircraft passes to the senior policeman present
I would also suggest that detaining pax on an aircraft with a possible bomb on board would breach article 73
A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein.