First reported by Brazilian fansite Potterish, it appears that Warner Brothers Brazil has leaked the news although it has yet to be confirmed.
Williams, who hasn’t scored a Harry Potter outing since Prisoner of Azkaban, is responsible for much of the most recognisable music in the franchise – most notably the recurring Hedwig’s Theme.
Should the news be confirmed, Williams will presumably replace Part 1 composer Alexandre Desplat for Harry Potter and the Deathly Hallows Part 2.