Oh come on...
If there was no truth to the allegations, he wouldn't have simply 'denied them' - he would have said he was suing their asses for defamation of character. But he didn't.
Everything points to Chris not being a very nice person. The judges don't like him (even Gary, who just says you have to stick by your act and shows no warmth or real belief towards him whatsoever). Not one other contestant shows any affection or friendship with him. I noticed when he was saved last week and went to hug some of the Union J boys they could barely reciprocate - as if they were repulsed.
I did feel sorry for him with the judges comments but they obviously really REALLY don't like him - and there has to be a good reason for that. Never before has such dislike been directed at one person from every judge (and it's a nightmare for poor Gary who has to stand by his act - but it's obvious that even he is struggling).