The Sun claims that Matt signed up for the panto back in January, seven months before the show began.
The Forum theatre in Barrow-in-Furness, Cumbria had promoted him as the star of its Christmas production of Peter Pan.
However, Matt ended up sailing through The X Factor - and last night he beat Saara Aalto to be crowned winner.
Now ITV bosses have apparently paid an undisclosed sum to buy Matt out of his contract with the panto's producer, Shone Productions.
If they hadn't, the 23-year-old may have been unable to complete the commitments he now faces after his victory.
Responding to a user on its Facebook page, The Forum confirmed: "Yes, he was originally playing Peter Pan.
"But unfortunately due to Matt's success on X Factor he is now unable to perform in this year's panto."
Matt was due to make his first appearance on stage on Friday - just two days before last night's live final.
He will now sign a contract with Simon Cowell's label Syco, and promote his winner's single, 'When Christmas Comes Around'.
The track, co-written by music superstar Ed Sheeran, has already reached the number one spot on iTunes.