The Voice bosses were left red-faced after they were caught watching rival series Britain's Got Talent while filming their own show.
TV executives were working on the Sunday night results edition of The Voice - which is pre-recorded following the live broadcast on Saturday - when the show's host Holly Willoughby discovered what they were watching.
According to The Sun, an audience member overheard Holly say: "Gallery, I can't believe you've got that on up there!"
A source told the newspaper, "People in the audience fell about laughing. Even The Voice bosses wanted to know who had won BGT."
The Voice's television staff made up some of the 13.8 million viewers who tuned in to see dancing dog Pudsey win Britain's Got Talent, compared with the 6.4 million who tuned into the BBC talent show.