Animal lovers are being warned not to be taken in by a cruel scam conning people out of money in exchange for puppies which never turn up.

Police are investigating adverts appearing in free publications that offer puppies for little or no money, other than transportation costs by courier from areas such as Scotland or Plymouth.

Anyone who answers the advert is asked to forward the courier costs via a money transfer service. When the puppy is not delivered and contact is made to the supplier - via a mobile telephone - the buyer is asked to send yet more money to ship the animal by a professional animal transportation company.

Police say no matter how much money is sent and regardless of promises made by the supplier, the animal will never be received. Meanwhile, the transferred funds are collected within hours of being sent and cashed overseas.

Jon Marriott of the Serious Economic Crime Unit said: "It's important to ensure that you know you have received goods before sending money in this way. If the offer sounds too good to be true, it usually is."

Anyone with information is urged to contact police on 01622 654374.