Sex, drugs and record roll for China's swim Sun-sation

 Beijing, Sun Yang's career has mixed tales of sex and drugs with jaw-dropping world records, but China's wild-child star will hope to stay clear of trouble as he anchors his country's Rio Olympics swimming assault.

If China's swimming team has a reputation for controversies, Sun is no exception, and the man who knows no equal over 1500m has often made headlines for his activities outside the pool.

Chief among his indiscretions was 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's rap sheet also includes clashing with officials over his affair with an air hostess, detention time for driving a Porsche SUV -- that was hit by a bus -- without a licence, and an altercation with a female Brazilian swimmer at last year's world championships.

Along the way, Sun lashed the national anthem of China's bitter war-time rivals Japan as "ugly", and turned heads by pulling out of the 2015 world championships 1500m final, again citing a heart problem.

But no one would argue with the athletic achievements of the 6ft 6in (1.98m) Sun, 24, who is acclaimed as China's most successful swimmer.

Sun became China's first male Olympic swimming champion when he won the 400m and 1500m freestyle at London 2012, where he also lowered his own world record over the longer distance -- after smashing Grant Hackett's decade-old mark at the 2011 world championships in Shanghai.

The two titles in London put Sun at the forefront of his country's best ever Olympic swimming performance, as China finished second behind the United States in the pool tally with five gold medals.

More glory could follow in Rio, although with China's swimmers taking part in few international events, their form is hard to assess. 

In London, China unleashed Ye Shiwen, then only 16, who won a sensational women's individual medley double including a new world record in the 400m race. 

Ye attracted doping innuendo -- strongly rejected by China -- after her final 50m burst in the 400m medley was quicker than American Ryan Lochte's when he won the men's gold a few races earlier. 

China's anti-doping procedures have also been in the spotlight ahead of Rio, after the World Anti-Doping Agency (WADA) suspended the accreditation of its national testing laboratory in Beijing in April.