UPDATE: Susan Boyle’s famous audition for Britain’s Got Talent was digitally tweaked, according to a show insider. The Evening Standard quotes an anonymous source saying that the show’s production team — which is the same as The X Factor — smoothed out the Scottish singer’s voice in post-production.

PREVIOUS: Talkback Thames, which co-produces Simon Cowell’s Britain’s Got Talent with his Syco, has admitted to me that the show has used Auto-Tune to make auditions sound better. (Auto-Tune is primarily designed to correct pitch and disguise off-key mistakes as well as filter outside noise.) This is now the 2nd Cowell contest show which is using sound enhancement technology and the 3rd  Cowell contest show which is cheating. “In line with standard television practice, sound filtering technology has been used on Britain’s Got Talent on our pre-recorded shows, but this does not unfairly reflect any singer’s performance. The performance shown on screen is a fair reflection of performance given in the live theatre.  Judges make their decision based on that live performance,” Talkback Thames emailed me. The producers are trying to split hairs; they claim the sound enhancement software is used only in post-production, and that Cowell and fellow panelists Piers Morgan and Amanda Holden do hear and judge only the performers’ raw efforts. But the audience is deprived of making fair comparisons about the contestants’ talent amid allegations that some singers are advancing because of interesting backstories instead of vocal ability. Even now, Talkback Thames is refusing to confirm or deny whether Britain’s Got Talent‘s most famous contestant, Susan Boyle, had her audition helped by Auto-Tune. That YouTube video of her performance garnered 120 million views, earning ITV an estimated $500,000 and making her a global singing sensation. But her success won’t feel so magical if it turns out her audition was Auto-Tuned as well.

Cowell’s UK version of The X Factor has been rocked by two cheating scandals already before it even airs on Fox in Fall 2011. The first coincided with the start of the new season when it was revealed that the show has been using Auto-Tune to make the audition contestants sound better. Many pop singers use Auto-Tune on their recordings or in live performance. But no one knew it was being used until a performance by 18-year-old contestant Gamu Nhengu who sang Katrina and the Waves’ 1980s hit “Walking On Sunshine”. After hearing her effort, judge Simon Cowell told her she was “really talented” before she was unanimously voted through to the next round, in part because of her compelling back story.That’s when fans crowded onto Facebook claiming they could clearly hear that vocal enhancements had been employed on Gamu’s voice and accusing the show of perpetrating a massive con. (“When she got going on the second verse, there’s a 10-second chunk where it’s really, really sharp and there’s an Auto-Tune moment.”) In response to the controversy, an X-Factor spokesman admitted that post-production work such as vocal enhancement technology was used. But he claimed it was needed because of all the microphones on stage to “deliver the most entertaining experience possible for viewers”.

A second scandal rocked the UK show after it emerged that a contestant already has a record contract in the U.S. Cowell, meanwhile, has been stung by all the criticism and banned performance-enhancing software from edited pre-recorded auditions. Still, UK newspapers are calling X Factor “the TV scandal of the year” and complaints have been lodged with UK regulators. On the one hand, all this cheating has attracted even more publicity and therefore rising ratings to Cowell’s UK shows. But how will Fox feel if Cowell’s credibility falls to zero?