The list of talented actors joining the Harry Potter TV series keeps getting longer as the Wizarding World is brought to life once again. Latest reports suggest that a familiar actor has been chosen to take over an important role in the Wizarding Universe.According to reports from The Sun, Bill Nighy (Lazarus) is set to take over the role of Professor Horace Slughorn in the upcoming series. It was previously announced that Nighy was taking over this role as a voice actor for the upcoming adaptation of J.K. Rowling's series by Audible.Keep reading to find out more about this casting report on the HBO Harry Potter TV series.Voice actor for Professor Slughorn reportedly cast to play the character in the Harry Potter TV series as well"Harlan Coben's Lazarus" London Screening - VIP Arrivals - Source: GettyIn the original Harry Potter movies, Bill Nighy played the role of the Minister of Magic, Rufus Scrimgeour, in the Deathly Hallows, Part 1. Therefore, reports revealing his addition to the voice cast for the Audible adaptation as Professor Slughorn were well received by the Potterhead fandom. On playing the professor in the audiobook, Nighy commented:"I was pleased to be asked to play the professor after having already played a minister for magic."However, recent reports from The Sun suggest that the actor who plays the Professor in the audiobook has also signed on to play Professor Slughorn in the Harry Potter TV series.In the J.K. Rowling series, Professor Slughorn doesn't become a part of the story until the very end. He joins the Hogwarts School of Witchcraft and Wizardry as the Potions Professor in Harry's sixth year at Hogwarts. He plays an important role in Harry's journey to understand Voldemort and his history. Therefore, the casting of the Professor so early on in the filming journey of the show is very doubtful, considering the show is only in Harry's first year at the moment.However, in Professor Slughorn's time at Hogwarts, we get another flashback scene with 16-year-old Tom Riddle, similar to the one in Chamber of Secrets. So, the Harry Potter TV series might've cast the role in an effort to shoot both flashback scenes early on in the journey to ensure that the actor playing Tom Riddle looks exactly the same, as the flashback scenes for Deathly Hallows Part 1 and Chamber of Secrets are set around the same time for 16-year-old Riddle. View this post on Instagram Instagram PostTherefore, while there is a slim possibility that Professor Slughorn's role will be cast so early on in the production process of the Harry Potter TV series, the flashback scene might be the contributing factor to such a decision.Nevertheless, the casting report from The Sun has not been confirmed by any official outlets for the TV series, so this is all speculation at this point, and we'll have to wait for an official announcement to make any assumptions about this casting.Keep reading Soap Central as we keep up with all the latest updates on your favorite TV adaptation!