Police in Norway is absolutely allowed to break the law to be able to catch the real culprits and not just the visible parts of criminal networks.
Here [1] is a case from April where the police imported 12 kg of cocaine as part of a deal with a man trying to smuggle the cocaine. The result was that they got the whole cell of Albanian smugglers and not just their german scapegoat.
[1] http://www.dagbladet.no/2016/04/28/nyheter/innenriks/kokain/...