I just got sent this and if it's true then it's worth being aware of it:
It has been confirmed by Royal Mail. The Trading Standards Office are
making people aware of the following scam:
A card is posted through your door from a company called PDS (Parcel
Delivery Service) suggesting that they were unable to deliver a parcel and
that you need to contact them on
0906 6611911 (a premium rate number).
DO NOT call this number, as this is a mail scam originating from Belize.
If you call the number and you start to hear a recorded message you will
already have been billed £15 for the phone call.
If you do receive a card with these details, then please contact Royal Mail
Fraud on 02072396655 or ICSTIS (the premium rate service regulator) at
http://www.icstis.org.uk <file:///\\www.icstis.org.uk>
Please circulate this to avoid anyone else being ripped off.