Marcus Belby
From Hpwiki
Marcus Belby is a seventh-year Ravenclaw student, "thin and nervous-looking" (HBP, page 137). His Uncle Damocles won an Order of Merlin and invented the Wolfsbane Potion, but Belby admits that he doesn't see his famous relation often. Belby was considered for entrance into the "Slug Club", but Slughorn finds his connections lacking. It is unknown whether or not Marcus is any relation of Flavius Belby.
Actor Rob Knox, who played Marcus Belby in the sixth Harry Potter film, The Half Blood Prince, was stabbed to death outside a London bar on May 25th 2008. He, along with his brother Jamie and friends were confronted by a 'crazed attacker' and was stabbed defending his younger sibling. The fight was believed to be over a mobile phone.
Knox had recently completed shooting the film when the tragedy occured. There is much controversy between the Knox family and Warner Bros. over whether or not to still show a particular scene where Rob Knox appears. Warner Bros. may be forced to edit footage in order to not screen "the boy who was stabbed to death" all over the world.

