Three years after it went off air,hugely popular game show Kaun Banega Crorepati's fourth season commenced here tonight with a grand party coinciding with its original host Amitabh Bachchan's 68th birthday. Clad in peach-coloured ethnic wear,a visibly moved Bachchan cut a huge birthday cake to mark the occasion. "It is a big day for Sony as well as me. I am returning to KBC after ten years and I feel like I am at home. Home is after all home,a source for joy and happiness," said the actor,accompanied by his daughter Shweta Nanda. He said he is at loss for words to express his gratitude towards his fans for their love and affection. "We have worked hard and the decision is now in the hands of audience," the actor said. The prize money for this season has been increased to Rs 5 crore. The show,based on the UK game show 'Who Wants to Be a Millionaire?',was first aired in 2000 and was hosted by Bachchan,his first appearance on television that revived his career. While the first two seasons were hosted by the Big B,the third episode of KBC was hosted by Shah Rukh Khan.