The winners of the show in 2009 returned for a special performance in Saturday night's show.
They put on a routine which referenced events from the year, including Black Lives Matter movement and the worldwide protests in the wake of the death of George Floyd at the hands of police in the US.
While many praised the amazing performance, over 10,000 have made complaints making it the second-most complained about TV moment of the decade.
In a response to the complaints, Diversity's Ashley Banjo said in a post on Instagram: "Art: The expression or application of human creative skill and imagination, typically in a visual form, producing works to be appreciated primarily for their beauty or emotional power.
"My truth, my platform, my art. I’ve always tried to create not only to entertain but also to inspire… That will never change."
He added: "I’m so grateful and overwhelmed by all of the love and support but also by the amount of conversation this performance has thrown up 🙏🏽 2020 has been such a historical year. One day we will look back and realise it was the start of real change..."
Ashley also responded to a message he was sent telling him to "entertain us and do not say anything about racism".
He replied: "1. You do not represent or speak for the Great British public.
"2. Silence was never and will never be an option.
"3. Change is inevitable... Get used to it"
Meanwhile his brother Jordan revealed the group had been "bombarded with messages and articles of horrible stuff about us, about our families, about how even now Diversity not diverse enough because there's only five white people in it."
He continued: "I feel really anxious and worried saying something like black lives matter when that's all we want man, love and positivity. No one is saying only black lives matter, as a son and as a dad. it's all positivity and love, let's keep it moving."
And Perri Kiely said: "I can’t believe the replies to this... apparently these people are adults!? Go educate yourselves."
You can watch their performance below...