Originally Posted by
Arctifox
That does seem like a quite strange approach. If some people would approch me at the airport and ask me for my CPR number I would be more than suspicious (except if they'd be police of course) - besides the legal point of view. Someone brought up the ticket inspectors on Swedish public transport, which I think is a different case: You are required to show a ticket when you use public transport, so if you don't have one you are clearly doing something wrong. But you are not required to give random people at the airport your CPR number - or am I wrong with that?
My first point of anyone asking for my CPR like that would be to ask for their credentials for doing so. I am guessing they are not uniformed police, so there is no knowing without asking. And while highly unlikely in the secure area in an airport , it could be a scam.
As for the legal rights, I don't not believe anyone but the police and customs officers can force you to ID yourself. The border checks are done by the police in Denmark. Even in the trains in Denmark I don't think they can force you to ID yourself, though they can detain you until the police comes.