The trio spread gossip about the Liverpool singer on The Xtra Factor, claiming that they had all heard reports about him misbehaving behind-the-scenes.
Maloney was the public's wildcard act on Saturday (October 6) and wasn't given a chance to respond to the allegations on the ITV2 spinoff show.
Walsh started the accusations, when he was asked who the biggest troublemaker was and if Rylan Clark was a diva.
"No, Rylan is not a diva at all backstage," said Walsh.
"I think Chris from Liverpool is a bit of a diva. That's what I'm hearing."
Both Contostavlos and Scherzinger backed Walsh up, claiming that they had heard the same rumour.
An annoyed Gary Barlow, who mentors Maloney, reminded his co-stars of the trouble they got in last year when they brought up backstage gossip to undermine Misha B. On that occasion, Contostavlos and Walsh described Misha as "a bully".
"Guys, we got into backstage gossip last year and it got us into a lot of trouble," said Barlow. "So let's not go there again."
Xtra Factor host Caroline Flack discussed the judges' comments on This Morning today, adding: "I get to know the contestants quite well, that's part of my job to become friends with everybody because we like to see a different side to them on The Xtra Factor, and I've never seen that side to him - he's always very, very pleasant to us so that is complete news to me, but I don't see them just before they are about to go on stage.
"Gary hates all the backstage gossip and it takes it back to last year with Misha B and the whole thing with her supposedly not being nice to the other contestants and it does change people's opinions... so sometimes it's not fair to bring out what goes on backstage, but sometimes people do wanna know."
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