Clark has been the subject of internet abuse and death threats during his time on the show and was most recently at the centre of last night's (October 7) dramatic results show.
Carolynne Poole was sent home after landing in the bottom two with Clark. Louis Walsh was criticised for appearing to save Poole before sending the vote to deadlock.
"Me and Rylan met when we filmed The Xtra Factor at his house, he's a great guy. He's having a bit of trouble at the moment with people tweeting and being abusive," Murs told The Sun.
"It's a shame really because I think he's really improved on the show and proven he's not just a gimmick act and he's a really nice guy. He's a top lad so I think he will do well."
"I mean nobody likes to read a tweet about them on the internet, that's horrible, and it's not what you want to see you know, but that's part and parcel of the industry unfortunately.
"For all the hundreds of thousands of tweets you get that are lovely and amazing, unfortunately you will always notice the one that's horrible. If you look at it, it is going to affect you in some shape or form."
Murs recently unveiled his new single 'Troublemaker'.
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