Monday night saw the live semi final stages of Britain's Got Talent 2019 begin.
One of the acts to perform yesterday was magic act The Haunting, presented by a mysterious woman called Elizabeth.
Her live performance saw her take Amanda Holden backstage before 'transforming' into Agatha behind her.
However eagle eyed fans watching on noticed how an awkward camera angle seemed to give away more than it should have.
As Amanda was led around the corridors by Agatha, viewers noticed Elizabeth peeking out from behind a stairwell.
One asked on Twitter: "Anyone else see The Haunting hiding around the wall to take over leading Amanda back to the stage? #BGT"
Another posted online: "You can see her round the corner of the wall 😂😂😂 #bgt"
"Camera angle wasn’t good at all for the haunting saw the woman come from behind the wall @BGT," tweeted a further viewer.
You can watch The Haunting's live performance on Britain's Got Talent in the video above.
Despite the hiccup, Elizabeth impressed the judges - especially after scaring Amanda so much she dropped the F-bomb live on air.
"We'd like to apologise if you heard any bad language there from Amanda, but she was very scared," Ant and Dec said after the performance.
"I just really want to apologise if I said anything... so massive apology. I can honestly say I feel terrified," Amanda said.
David Walliams praised the performance: "It was stunning. the performance was out of this world, it was terrifying."
Alesha Dixon added: "I feel really bad because Amanda's genuinely shaken up. It was so scary and intense. It was thrilling to watch."
Simon Cowell remarked: "Compared to everyone else so far, this is by far the most interesting act by a while we've seen.
Elizabeth went on to make the Top 3 of the public vote but didn't make the final with mind reading dog act Dave & Finn and David's golden buzzer act Flakefleet Primary School making the cut.
Other acts in Monday's first semi-final were rollerblading duo Rosie and Adam; dancing group Khronos Girls; comedy impressionist Tony Rudd; singer Brian Gilligan; and Ant and Dec's choice, dancer Akshat Singh.
Britain's Got Talent airs live all this week at 7:30PM until Friday. The live final airs on Sunday.