Prince Harry and Kate play Batman and Harry Potter at new theme park outside London

The Duke and Duchess of Cambridge and Prince Harry tour the Warner Bros studios near Watford where the Harry Potter films were made, with Prince William trying out the Batmobile and Batman's bike, the Batpod.

The Duke and Duchess of Cambridge and Prince Harry were all smiles as they arrived at the studios where the Harry Potter films were made for a morning of playing with props

The royal trio were chauffeur-driven to officially open the Warner Bros studios where the popular movies were produced along with other famous films.

The Duchess, who is around six months pregnant, wore a black jacket and a £38 polka dot dress from Topshop and she, Prince William and Prince Harry were introduced to local dignitaries and senior executives from the film studio.

The large sprawling site close to Watford is home to the popular Making Of Harry Potter tour that has proved a huge attraction for fans of the teenage wizard.

Props, costumes and models from the movies that chronicle his adventures were on display for the royal guests.

Also invited for the visit were 500 children, and their parents, associated with charities that have one of the royals as their patron.

Props from other Warner Bros films were also on display, including the Batmobile and Batpod from the Dark Knight Batman trilogy.

Prince William joked about taking over the Batman role with Josh Berger, president and managing director of Warner Brothers UK, Ireland and Spain, telling him: "Christian Bale's getting old and tired... I will stand in if I have to.

He could not resist jumping on the Batpod and he leaned forward and gripped the handlebars of the vehicle as Prince Harry and Kate looked on.

The Duke joked "where's the start button?", adding "it's awesome, absolutely incredible" while his younger brother put his fingers beside his head for Batman's ears and said "you need the ears".

When Prince William finally emerged from his fun, he said: "I'm a very happy man" but he then spotted his wife and apologised, saying: "sorry, sorry".

Source: ITN/PA