Twins Brooks Way were absent from the first X Factor live show on Saturday night after reports that one of the duo allegedly sent threatening messages to an ex-girlfriend.
Seventeen-year-olds Kyle and Josh Brooks were due to perform as part of Louis Walsh's 'groups' category on Saturday's programme.
A spokesman said their performance was pulled due to information "given to the show regarding one of the group".
When the show began, host Dermot O'Leary told viewers that "due to unforeseen circumstances the Brooks brothers will not be performing this evening".
During the programme the pair tweeted from their official account, saying: "Such a shame we can't be there tonight ... hope everyone is enjoying the show." The tweet has since been deleted.
Due to circumstances that have arisen, Brooks Way will not be appearing on tonight's #XFactor show
— The X Factor (@TheXFactor) October 8, 2016
Last week, The Sun on Sunday reported Josh Brooks had been involved in an altercation with a girlfriend at a party on New Year's Eve.
The singer told the newspaper: "A fight broke out between me and another male at a party. Amelia, along with others, tried to break it up.
"She was accidentally knocked in the process. It was never my intention to hurt her or put her in danger - and this situation is way out of my character."
The first live show on Saturday night saw controversial contestant Honey G centre stage with her version of Tupac's California Love.
Judge Walsh said the late rapper "would be happy" with her tribute, but Nicole Scherzinger said Tupac would be "turning over in his grave".
Show boss Simon Cowell said: "I don't know what just happened ... but here's the weird thing, I loved it."
Judge Sharon Osbourne was left red-faced when she introduced one of her acts, Finnish singer Saara Aalto, as Norwegian.
"She's come all the way from Norway," said Osbourne before the audience and fellow judge Walsh corrected her.
