Our exclusive jackpot tracker picked up the win, which is the second win we've recorded for the game. The game appears to have either been hit at Gala Casino or Paddy Power, although we won't know for sure until the details are revealed. The game's only other win came at Gala earlier this year for £1.7 million.
The Glass Slipper Jackpot is won when five glass slippers are unveiled on a single payline.
We'll be updating this story as more developments arise.
Related: The Glass Slipper Jackpot