If contact is by cellphone and email only and electronic payment is requested in advance the most likely explanation is that the speakers do not exist at all.

It would be vary hard to make fake Lab5's  that couldn't be detected within 5 minutes of listening to them.  

Simon 

I would have the opportunity to see&test the speakers. No mail order I pay cash & carry the speakers. No shady address.

Just curious: Which sound is the speaker making while measuring the room with the built-in speaker. Is there any MP3 recording available on the net to check against the offered speakers. 

 I have the serial numbers and contacted B&O but they do not have a list of stolen items. They told me I have to contact the dealer in question.

Xing
 

If they are stolen, then they'll be stuck in PIN code protection, so ask if you can see/hear them working first. If he refuses, then the likelihood is they're stolen. Or you could ask him for the serial number so you can check 'which version they are', and then ring a dealer to see if they're registered as stolen.

Either way, they aren't 'fakes'. They'd be too difficult to build...

Remember the old saying "If it is too good to be true, then it is"

Craig🙂

Really? Never heard of that before, I wonder why they'd remove the innards?