The Rio Olympics have yet to begin and swimming's enfant terrible Sun Yang has already courted controversy after claims the Chinese giant tried to intimidate Australian rival Mack Horton during training. Olympic champion Sun, whose hot temper has landed him in trouble before, was said to have splashed water at Horton during a practice session, just days before they face off in the men's 400 meters freestyle. The allegation was denied by China, team manager Xu Qi telling the state-run Xinhua news agency: "It is fake news — Sun Yang and the Australian swimmers are very good friends." However, such claims come as little surprise given Sun's lengthy rap sheet. The 24-year-old was previously banned from swimming for six months after being arrested for driving his Porsche without a license. That episode followed a public bust-up with his coach, who voiced disapproval of the hulking swimmer's relationship with a flight attendant. Sun also found himself in hot water at the Asian Games two years ago after ripping into the national anthem of China's fierce rival Japan, calling it "ugly" before eventually apologizing for his remarks. At last year's world championships in Kazan, Sun was involved in a row with the Brazilian swim team when he was accused of bullying Larissa Oliveira, who claimed he tugged her foot during warm-up in a fit of pique. Among his many previous indiscretions are a three-month doping suspension in 2014 — served in secret and announced retrospectively — for taking a banned stimulant, which he said he needed for a heart complaint. Sun, who won gold in the 400m and 1,500m freestyle at the 2012 London Olympics to become his country's first male Olympic swimming champion, will be among the favorites to win those events again in Rio. His breakout performances in London helped China finish second behind the swimming superpower the United States with five gold medals compared to 16 for the Americans.