The group, who appeared on last weekend's BGT auditions show with their trampolining basketball act, had previously worked for Cowell and alongside Ant & Dec on their ITV1 big-money quiz Red or Black?
Face Team competed in a game of Red or Black? where they had to see who could do the longest slam-dunk off a trampoline.
However, on Saturday's BGT Ant & Dec and Simon Cowell appeared to have no idea who the Hungarian group were.
Viewers quickly complained on Twitter, claiming that the group were clearly getting special treatment from Cowell, who awarded them a pass to the second round of the competition.
However, a show source has denied any wrongdoing or favouritism and told The Sun newspaper that Cowell was unaware of the act because he was in the US when the group appeared on Red or Black?
The source added: "Face Team were booked by ITV Studios, not Simon's company Syco. There's nothing to stop an act that appeared on Red or Black? performing on BGT.
"Simon didn't say anything like, 'I have never seen this', like the other judges and in fact said they had to improve."
Britain's Got Talent's audition shows continue this weekend at the slightly later time of 8.30pm on ITV1.
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Watch Face Team's Britain's Got Talent audition: