Novak Djokovic says match-fixing is not prevalent at the top level of tennis, as allegations of corruption overshadow the start of the Australian Open. The world number one, who says he rejected £110,000 to lose a match early in his career, says there is “no real proof” of fixing among the elite. “It’s just speculation,” said the Serb 10-time Grand Slam champion. BBC and BuzzFeed News are said to have obtained secret files that contain evidence of suspected match-fixing in tennis. The coming days will tell.