The group consists of 15 boys and 1 girl, and many have links to The X Factor, BGT's sister show.
They include their choreographer Dean Lee, who has also worked on the singing contest, and lone girl Yasmin Crotch, who has previously appeared as a backing dancing on the ITV1 series.
“There are rumblings of discontent from other acts that show staff know the choreographer and that this could prove beneficial as the competition progresses," a source told The Sun today.
Dean has also performed on The X Factor UK and the live tour, as well as helping out the show's creative director Brian Friedman.
A spokesperson for the show last night dismissed any claims of favouritism from the other acts.
They said: “To claim that this gives the group any advantage is ridiculous and totally untrue.
"The fact is that Four Corners is a fantastic act and viewers will see this for themselves on the show. The group have got where they are on their own merits.”
Meanwhile a source on the show revealed that the group were found on YouTube, not through links from The X Factor.
The insider told the tabloid: “Four Corners were discovered by a researcher looking at YouTube – nothing to do with the choreographer. Going forward we can assure that this does not give them any advantage.”