Fans appeared to be adamant that Jack – who has shunned the limelight for the past few years – has undergone cosmetic surgery.
Before the post was pulled down, followers speculated that the talented singer has undergone all manner of procedures; including lip injections, botox and fillers.
“Jack has had some work done on his face it seems,” wrote one person. “Definitely not the same person anymore.”
'He's had so much cosmetic procedures doesn't even look like him,' wrote another person.
'Those lips are definitely not natural,' wrote one person, while another added, 'Guess all his prize money was spent on filler!'
However, Jack’s fans comments are merely speculation, and the singer has previously denied ever going under the knife.
After fans asked in 2017 if he'd had work done, Jack tweeted: "OMG have people heard of a thing called puberty?"
And even his own mother jumped to his defence, writing on Facebook this week: "Jack has never had even one cosmetic surgery procedure.. he has gone from a little boy to a man.. his looks changed because he grew up!"