England's limited-overs coach Ashley Giles has denied his players tamper with the ball after allegations made by former captain Bob Willis. Giles spoke yesterday for the first time since Willis claimed the ball was changed during Thursday's Champions Trophy defeat to Sri Lanka because it had been tampered with. "Let's not beat about the bush - [umpire] Aleem Dar is on England's case. He knows that one individual is scratching the ball for England - who I am not going to name - and that's why the ball was changed," Willis said live on Sky Sports. Giles strongly denied the accusations and was unhappy they had surfaced ahead of today's must-win Champions Trophy clash with <a href="gopher://topicL3RoZW5hdGlvbmFsL09yZ2FuaXNhdGlvbnMvU3BvcnRzIHRlYW1zL0NyaWNrZXQgdGVhbXMvTmV3IFplYWxhbmQ=" inlink="topic::L3RoZW5hdGlvbmFsL09yZ2FuaXNhdGlvbnMvU3BvcnRzIHRlYW1zL0NyaWNrZXQgdGVhbXMvTmV3IFplYWxhbmQ=">New Zealand.</a> "We don't tamper with the ball and I hope we can talk about something else," Giles told a news conference. "It is disappointing because we have a huge game, a quarter-final. It is must-win, and there are a lot of headlines about the wrong stuff. "With the situation the other day, the ball was changed because it had gone out of shape. We asked the question, the captain asked that question to the umpires, which he has a right to. The ball was changed, the rest is history." Willis, England's second all-time leading wicket-taker in Tests, went on to question the reasons given, adding: "Have you ever heard of the batting side complaining about the shape of the ball, or the umpires saying 'we're going to change the ball because it's out of shape'? "The bowling side change the ball because it's out of shape because they think it's gone soft. That's the reason, pure and simple. How naive does Alastair Cook think we are? The ball was changed because it was out of shape? He didn't want the ball changed, so why was it changed?" Giles, however, refused to be drawn into a war of words. "People have the right to say what they say, we can't stop them," he said. "It sounds boring, but we have to focus on what we want to do. The most important thing is winning cricket matches and not what Bob Willis says." In reference to Willis's claim that a particular player was responsible, Giles said: "There has even been mention of one of our players having a specific role. That player is an extremely good player and we'd like to let him concentrate on cricket." England must beat New Zealand in Cardiff to seal a semi-final spot. If they lose they are out and either Australia or Sri Lanka will go through, along with New Zealand, after their match tomorrow. If the England-New Zealand match is a washout they will need a low-scoring Australia victory to go through. If both matches are washed out, England will qualify behind New Zealand. Follow us