"It was my understanding," Shacklebolt revealed, "that Miss Granger was the one responsible for ensuring Mr. Malfoy ingested the Suppression potion daily while at Hogwarts. We already know that Malfoy, along with his father, held a lowly opinion of Granger due to her Muggle-born blood status. It makes sense that the embittered Malfoy would want to take advantage of her for his own gain. There are many old types of ancient family magic, and what is more commonly referred to as "Blood Magic,’ that would allow for Malfoy to bypass the magical restrictions of his probation, allowing him to harness wandless magic and perform combined dark spells after having impregnated Miss Granger."