Ofcom have confirmed that a total of 23,308 people have complained about the routine - which featured a strong reference to the death of George Floyd in the US earlier this year.
The dance - which was choreographed by Diversity's Ashley Banjo - is currently the second most complained about TV moment of the decade.
Several celebs have come forward to show their support for Ashley and co, including BGT judge Alesha Dixon - and now ITV have done the same.
An ITV spokesperson told Daily Star Online: "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 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."
Meanwhile, a ITV insider told The Sun Online that ITV have been inundated with "many messages of support" from fans who were touched by the performance.
BGT judge Amanda Holden confirmed it during an appearance on Good Morning Britain this week and said the team have received "100,000s" of positive messages about the dance.
"It is extraordinary. I think the number of negative complaints means this conversation is right and needs to happen," she said.
"What hasn’t been reported is the positive response - hundreds of thousands of them. We stand by them and stand by Ashley Banjo 100 per cent."
Her comments come after her pal and fellow judge Alesha apparently said she "would quit if ITV apologised for the performance".
A source told the Mail Online: "Alesha is absolutely furious and doesn’t think anyone should be apologising for anything.
"Ashley is in a complete state over all of this and it has knocked his confidence. Alesha has spent the week supporting him and building him back up.
"She is very sad about it all but staunchly stands by the dance. It is something she feels incredibly passionate about so if ITV were to say sorry, it would be understandably hard for her to continue," they added.
BGT continues on Saturday at 8pm on ITV.