The first pictures of Naomi Watts as Princess Diana have emerged online.The Oscar-nominated Australian actress, whose big screen credits include Mulholland Drive and The Ring, has been photographed on the set of Caught in Flight in Croatia.The Oliver Hirschbiegel-directed drama will centre on the last two years of the Princess's life as it explores her alleged affair with heart surgeon Dr Hasnat Khan.Watts said of her casting: "It is such an honour to be able to play this iconic role - Princess Diana was loved across the world, and I look forward to rising to the challenge of playing her on screen." AP