In the Harry Potter and the Prisoner of Azkaban video game, you can get two famous hag cards of Malodora Grymm and Leticia Somnlens and their tales are based on Snow White and Sleeping Beauty respectively.
The Leticia Somnolens page says:
Her story appears to be the source of inspiration for the Muggle fairytale Sleeping Beauty.
And the Snow White page says,
This Tale seems to be an actual account of the incident caused by Malodora Grymm in the Middle Ages.
Now, in the world of Harry Potter, if they ARE the basis for such tales, then their respective authors, Brothers Grimm and Charles Perrault, cannot reveal that for that would breach the Statute of Secrecy, so maybe they lie about where the get their stories from.
Is that right?