An unedited version of Prince William's photograph posted on his website has revealed his cheeky nickname "Big Willy" inscribed on a mug at an RAF base.

An uncropped version of the photograph of William, 30, part of a set issued by St James's Palace on the Duke's website, reveals his nickname on the mug at Royal Air Force (RAF) Valley on Anglesey, north Wales.

The photo was first issued last November with the mug title cropped out and that release followed a Ministry of Defence security blunder that saw sensitive information visible in some earlier photos.

The new version of the photograph of Flight Lieutenant Wales is visible on the Duke's website, along with the mug title, the Daily Mail reported.

The Daily Star newspaper has claimed that the nickname was first given to him by his wife Kate.

The Duchess of Cambridge, was nicknamed "Waity Katie", because they were together for a decade before marrying and she had to sit out the years before William proposed.

The caption on the cropped photograph issued by the Press Association last November said: "The Duke of Cambridge making a cup of tea whilst working as a helicopter search and rescue pilot at RAF Valley on Anglesey, Wales."

It added that the undated picture was part of a "day in the life" set of photos featuring William in his work flying RAF Sea King helicopters from RAF Valley as a Search and Rescue pilot.

The MoD was forced to reset the user names and computer passwords of dozens of RAF staff following an embarrassing security blunder over the William pictures last November.

The photographs were 're-released' with the details pixelated, but the MoD had no choice but to reset passwords of some personnel 'as a precaution'.
As royal nicknames go it is not too bad. Princess Diana was called Squidgy by a close male friend.

Charles and Camilla call each other Fred and Gladys.
Back in their schooldays William's nickname was "Wombat" and 31-year-old Kate's was "Princess in waiting".