Simon Cowell is not a happy bunny after it was revealed that the winning act of this year’s Britain’s Got Talent wasn’t as it seemed. In case you missed it, dog trainer Jules O’Dwyer admitted to using stunt dog Chase for part of her and Matisse’s winning performance (the part where Matisse appeared to walk on a tightrope). During an interview on Lorraine on Monday, she explained: “Matisse is a bit afraid of heights so although he could officially do it, Chase is the action dog, so he plays the double.” Jules and Matisse were crowned winners on Sunday (image: ITV). As well as rubbing the public up the wrong way, Simon is also said to be angry about the whole situation and is allegedly launching an investigation to find out why producers kept it a secret. A source told The Sun newspaper: “He is shocked and angry. He had no idea. He wants to know who is responsible. Heads could roll.” The duo won over the hearts of viewers (image: ITV). Jules has since defended her decision to use another dog, saying: “I’m creating a story. It’s the magic of the whole act. It’s not that we were trying to mislead people, we were trying to entertain. “Matisse can do all those things. I chose not to do that on the night because I chose to split the act up so as not to over-work my dogs, so every dog can take a role.”