Saturday night's semi-final drew 277 complaints to Ofcom, with the broadcasting regulator confirming to LADbible that 235 of these related specifically to Holden's attire.
She was wearing a full-length blue sparkly gown, which had a low-cut neckline - which some viewers found a 'little revealing', while others argued they could see a bit more than they bargained for.
Holden, 49, has since addressed the décolletage debacle on Instagram, telling fans that her nipples were nowhere near the cleavage line of her dress.
Sharing a screenshot of a recent news story about the dress, Holden wrote in an Instagram Story: "Mmmm really?! Who has nipples this close to their cleavage?!"
I mean, she's got a point.
"FYI. A boned corset dented the girls all night," she added, with two fried egg emojis confirming 'the girls' are, indeed, her breasts.
While some social media users complained about the dress, others argued what could be seen was merely a shadow - likely from Holden's microphone, which was attached to the front of her dress.
Britain's Got Talent has received complaints for various reasons recently, including backlash for another judge's fashion choices.
Following an episode in which Alesha Dixon donned a Black Lives Matter necklace, Ofcom confirmed it received almost 2,000 complaints.
The specific nature of the complaints has not been revealed, with a spokesperson from the broadcasting watchdog telling LADbible: "We are assessing these complaints against our broadcasting rules, but are yet to decide whether or not to investigate."
Ofcom also received more than 24,000 complaints over Diversity's performance inspired by the Black Lives Matter movement, which referenced the killing of George Floyd in the US.
It became the second most complained about TV moment of the decade, but Ofcom said it would not be investigating - while ITV said it would be standing by Diversity and supported the dancers.
A statement said: "Britain's Got Talent has always been an inclusive show, which showcases diversity and supports strong storytelling in all forms and ITV stands behind the decision to broadcast Diversity's performance on BGT.
"Ashley [Banjo] and the group are a great example of the talent, creativity and diversity of modern Britain and their performance was an authentic, heartfelt response to many of the issues and events which have affected society in 2020."
Britain's Got Talent returns this Saturday (3 October) for the last semi-final, with the final airing the following week on Saturday 10 October.