Question: Who directed the 1968 thriller film that featured the actor of the "Harry Potter" films' Rubeus Hagrid in a supporting role?

Context paragraphs:
Harry Potter and the Philosopher's Stone (film): Harry Potter and the Philosopher's Stone (released in some countries as Harry Potter and the Sorcerer's Stone) is a 2001 British-American fantasy film directed by Chris Columbus and distributed by Warner Bros.  Pictures.  It is based on the novel of the same name by J. K. Rowling.  The film is the first instalment in the long-running "Harry Potter" film series, and was written by Steve Kloves and produced by David Heyman.  Its story follows Harry Potter's first year at Hogwarts School of Witchcraft and Wizardry as he discovers that he is a famous wizard and begins his education.  The film stars Daniel Radcliffe as Harry Potter, with Rupert Grint as Ron Weasley, and Emma Watson as Hermione Granger.

Harry Potter (film series): Harry Potter is a British-American film series based on the "Harry Potter" novels by author J. K. Rowling.  The series is distributed by Warner Bros. and consists of eight fantasy films, beginning with "Harry Potter and the Philosopher's Stone" (2001) and culminating with "Harry Potter and the Deathly Hallows – Part 2" (2011).  A spin-off prequel series will consist of five films, starting with "Fantastic Beasts and Where to Find Them" (2016).  The "Fantastic Beasts" films mark the beginning of a shared media franchise known as J. K. Rowling's Wizarding World.

Defence of the Realm: Defence of the Realm is a 1986 British political thriller film directed by David Drury, starring Gabriel Byrne, Greta Scacchi, and Denholm Elliott, with Robbie Coltrane in a supporting role.

Harry Potter and the Deathly Hallows – Part 2: Harry Potter and the Deathly Hallows – Part 2 is a 2011 British-American fantasy film directed by David Yates and distributed by Warner Bros.  Pictures.  It is the second of two cinematic parts based on the novel of the same name by J. K. Rowling.  The film, which is the eighth and final instalment in the "Harry Potter" film series, was written by Steve Kloves and produced by David Heyman, David Barron, and Rowling.  It is the sequel to "Harry Potter and the Deathly Hallows – Part 1".  The story continues to follow Harry Potter's quest to find and destroy Lord Voldemort's Horcruxes in order to stop him once and for all.

Lego Harry Potter: Lego "Harry Potter" is a Lego theme based on the films of the "Harry Potter" series.  Lego models of important scenes, vehicles and characters were made for the first six films and all the books released.  The first sets appeared in 2001, to coincide with the release of the first film "Harry Potter and the Philosopher's Stone" (Harry Potter and the Sorcerer's Stone in the United States).  Subsequent sets were released alongside the new films, until Harry Potter and the Order of the Phoenix.  The line then went dormant for three years.  It is unknown if the theme will again be revived to coincide with future installations in the Harry Potter franchise, such as the film Fantastic Beasts and Where to Find Them.

Robbie Coltrane: Robbie Coltrane, OBE (born Anthony Robert McMillan; 30 March 1950) is a Scottish actor and author.  He is known for his roles as Rubeus Hagrid in the "Harry Potter" films, as Valentin Dmitrovich Zukovsky in the James Bond films "GoldenEye" and "The World Is Not Enough," and as Dr. Eddie "Fitz" Fitzgerald in the British TV series "Cracker" during the 1990s.

Rubeus Hagrid: Rubeus Hagrid is a fictional character in the "Harry Potter" book series written by J. K. Rowling.  He is introduced in "Harry Potter and the Philosophers Stone" as a half-giant and half-human who is the gamekeeper and Keeper of Keys and Grounds of Hogwarts, the primary setting for the first six novels.  In the third novel "Harry Potter and the Prisoner of Azkaban", Hagrid is promoted to Care of Magical Creatures teacher, and is later revealed to be a member of the Order of the Phoenix.

Harry Potter and the Chamber of Secrets (film): Harry Potter and the Chamber of Secrets is a 2002 British-American fantasy film directed by Chris Columbus and distributed by Warner Bros.  Pictures.  It is based on the novel of the same name by J. K. Rowling.  The film is the second instalment in the long-running "Harry Potter" film series.  It was written by Steve Kloves and produced by David Heyman.  Its story follows Harry Potter's second year at Hogwarts School of Witchcraft and Wizardry as the Heir of Salazar Slytherin opens the Chamber of Secrets, unleashing a monster that petrifies the school's denizens.  The film stars Daniel Radcliffe as Harry Potter, with Rupert Grint as Ron Weasley, and Emma Watson as Hermione Granger.  The film is also the last film to feature Richard Harris as Professor Albus Dumbledore, due to his death that same year.

Sam Clemmett: Sam Clemmett is a British actor.  Born in Brundall, Norfolk, Clemmett began his acting career in 2013.  He is known for being cast as Albus Potter in 2015 for the British play Harry Potter and the Cursed Child.  His performance in the play has made him popular with Harry Potter fans, as well as the creator of Harry Potter, J.K. Rowling.  Rowling stated that, "There's much I could say about Sam-as-Albus, but we'd be into spoiler territory so quickly I'll just say we couldn't have cast better."  He played the role in the West End, until late-Spring 2017.

PotterCast: PotterCast is the official podcast of the "Harry Potter" fansite The Leaky Cauldron.  Its episodes are posted once per month and are typically about an hour long.  In every episode, the hosts discuss particular passages, themes, and questions from the Harry Potter books and films, and they go over the Potter-related news stories reported during the previous week by The Leaky Cauldron.  The podcast often includes input from everyday Potter fans, but it has also featured numerous interviews with professionals involved in making the Potter books, films, and video games.  PotterCast frequently hosts contests, and it has presented a variety of themed shows, including a special wizard rock video edition and an episode for Banned Books Week 2005, in which staff interviewed representatives from the American Library Association.  It also covers breaking news, such as the press conference hosted by Warner Brothers before the release of "Harry Potter and the Goblet of Fire".

Supporting paragraphs: Defence of the Realm Robbie Coltrane
Answer: David Drury