The Sun: 'Nothing is being left to chance after this positive test. A lot of money has been spent on ensuring everyone on the show has access to testing.'If required, those taking part could even undergo daily checks to make sure they remain virus free.'The key thing for producers is knowing that if a case emerges that they can react to it to make sure it doesn’t become a massive crisis.'The source added that the 'nightmare scenario' is a case going 'undetected' and 'spreading' throughout both cast and crew.The Sun has also claimed that bosses have a list of 'stand-by' celebrities for the show in case a star falls ill with relatives likely banned from rehearsals and no live studio audience allowed.