St James's Palace released photographs of Prince William at work yesterday, only to remove them hours later because they accidentally revealed confidential air force passwords.

Ten photographs of William were published on the Duke and Duchess of Cambridge's new website, showing the future King at work as an RAF search and rescue pilot.

The images were removed just four hours later, when it was revealed that sensitive information — including the passwords of several RAF personnel — was visible on computer in the background of four of the shots.

By that time, the images had been republished by thousands of websites, TV networks and newspapers around the world, forcing the Ministry of Defence to reset all RAF usernames and passwords to avoid a security breach.

"Due to an administrative oversight, these photographs were not properly cleared at RAF Valley and the images showed unclassified MoD user names, passwords and computer screens on a restricted system," a Ministry of Defence statement read.

"The passwords and user names shown have now been reset as a precaution."

The shots have since been re-released, with the classified information pixelated.

They show a day in the life of William at RAF Valley in Anglesey, Wales, making tea and sharing a joke with his colleagues.

William's days in the RAF appear to be numbered. Royal sources claim the Duke will give up his job at the end of the year to become a full-time royal.

He and Kate are poised to give up their beloved rented Anglesey farmhouse and move full-time to their new apartment at London's Kensington Palace.

Prince Harry will also move, from his father's quarters at Clarence House to a cottage in the grounds of Kensington Palace, which has been William and Kate's London base since their marriage last year.