"One freckle-faced six-year-old left the hall in tears. 'I loved stooging,' he sobbed to the Daily Prophet. 'Me and me dad like watching them Keepers flattened. I don't want to go to Quidditch no more.'"
↑He mentions that he and his father like watching Quidditch, meaning his father is a wizard (though his blood is unknown), meaning as this boy has at least one wizarding parent he cannot be a [Muggle-born].