Calvin Harris has apologised after being kicked out of The X Factor studios for running on to the stage during John And Edward's performance.

The musician joined the twins on stage, brandishing a pineapple on his head and bending over to point at his rear end.

The twins kept going despite the unexpected interruption, prompting their mentor Louis Walsh to later say: "When the idiot jumped up from the audience it didn't even faze you guys."

Presenter Nick Grimshaw was drafted in at the last minute to replace Calvin on the panel on ITV2's The Xtra Factor, after the singer was told to leave.

Holly Willoughby said: "He used to get all the girls. Now he just gets kicked out. He's been shown the back door quite promptly."

Interviewed afterwards, John and Edward said they had initially thought Calvin's stunt was "part of the show".

When Holly said the pineapple was supposed to be an imitation of their hairstyle, they said: "At least he did a good job."

Journalist Grace Dent, who sat next to the Acceptable In The 80s star during the show, said of his stunt: "I'm not condoning it, but it was really funny."

A spokesperson for The X Factor said: "Calvin Harris (a guest on tonight's The Xtra Factor) ran onto the stage during John And Edward's performance. This resulted in him being escorted from the studio by security and ejected from The Xtra Factor as a planned guest. Apparently Calvin is a huge John And Edward fan but it's unacceptable to storm the stage whilst an act is performing."

Calvin later tweeted: "At the end of the day, I had a pineapple on my head. Sorry if I caused anyone embarrassment. Ps. I love Jedward."