Tyson Fury ahead of his fight with Dereck Chisora on November 6, 2014 in Bolton, England. Pic/Getty Images

London: Tyson Fury has announced his immediate retirement from boxing. The 28-year-old, whose career has been mired in controversy since he unexpectedly defeated Wladimir Klitschko for the IBF, WBO and WBA heavyweight titles, dismissed the sport as "a pile of s**t" and "the saddest thing I ever took part in" in a post on his Twitter account yesterday afternoon. He had been scheduled to earn the biggest purse of his career in a rematch with Klitschko at the Manchester Arena on October 29.