Musician Calvin Harris was removed from the X Factor studio last night by security guards after running onstage during John and Edward Grimes’ performance.
An X Factor spokesman said: ‘Apparently Calvin is a huge John and Edward fan but it's unacceptable to storm the stage whilst an act is performing’.
Harris had been due to appear on the sister show The Xtra Factor.
In the run-up to last night's show, Simon Cowell was heavily criticised for missing the chance to kick the twins off the show last week.
He let the public vote make the final decision and it was Lucie Jones who instead waved goodbye.
Before their performance, he said he was ‘praying they are fantastic’ for the first time.
Cowell added: ‘There's something about these two. The fact that they have just kept on and on and on.
"They have won me over a little bit.’
He also took the opportunity to explain his decision to allow last week's eviction from the show to be decided by the public vote.
‘I would never ever play tactics or mess with people's lives, I've even thrown out my own contestants in this position before,’ he said.
‘I took a decision because I didn't feel strongly enough about either performance.
‘I didn't know what was going to happen but one thing I can say is I trust the public, I always have I always will.’
He admitted it had not been a popular decision and sent a personal message to Lucie Jones who was sent home by the viewers' vote: ‘Lucie I want to say this to you, even though I'm sorry that you left, you left with dignity.’