Britain's Duke and Duchess of Cambridge have adopted a puppy.

While Prince William was believed to have bought his wife a Labrador to celebrate her 30th birthday earlier this month, a spokesperson for the couple has confirmed to the Daily Express newspaper that the latest addition to their family is actually a Cocker Spaniel.

They have not announced the name of the pet.

The couple have been spotted out walking with the dog near their home in Anglesey, Wales and onlookers said they appeared besotted with the pup.

A source said: "The dog is ever so cute. The duke and duchess have been seen with it several times and he runs along at their heels.

"They are constantly in fits of laughter as it tries to catch them up."

The couple are known to be dog lovers and both kept the animals as pets when they were growing up with William owning a black Labrador named Wigeon.

Catherine's family are fans of Cocker Spaniels while William's father Prince Charles has previously adopted a Jack Russell Terrier named Beth with his wife Duchess Camilla from the Battersea Dogs & Cats Home in London.

William's grandmother Queen Elizabeth is known for her love of Corgis.