The agency said Sun had tested positive for trimetazidine, a
substance normally used to treat angina. The stimulant was added to
the World Anti-Doping Agency's (WADA) banned list this year.
"I have taken many doping tests during years of training and
competition and I had never failed one before," Sun told China's
official Xinhua news agency.
"I was shocked and depressed at that time, but at the same time it
made me cherish my sporting life even more. I will take it as a
lesson and be more careful in the future."
CHINADA said Sun tested positive in May during the national swimming
championships and although the result was "not very serious" it
still warranted a penalty.
Sun was also fined 5,000 RMB ($816) while officials from his
provincial swim team were also handed unspecified penalties.
“Sun Yang in this matter was not completely responsible and the
positive test is his mistake, but the mistake is not very serious or
negligent," CHINADA deputy director Zhao Jian said.
"Because of this, the three-month ban is reasonable."
Xinhua said Sun had waived his right to have his 'B sample' tested
but had defended himself at a hearing in July, saying he had been
prescribed the drug for heart palpitations he has suffered since
2008 and was unaware that it was recently banned.
Trimetazidine was added to WADA's banned list, which is updated
annually, in January this year as an "example to reflect emerging
patterns of drug use."
'HUGE BAD NEWS'
Sun served his suspension in time to represent China at the Incheon
Asian Games in South Korea in late September, where he won three
He did not mention the suspension in Incheon and CHINADA said it did
not immediately announce the sanction because it only reveals
positive tests every three months.
[to top of second column]
"Sun is the most famous athlete in China and is known in the world,
which means we need to handle his case very cautiously. This is huge
bad news but we will not cover it up," said Zhao.
"We announce positive cases and test statistics in our quarterly
reports just as WADA requires."
Sun burst into the international spotlight when he won the 400m and
1,500 freestyle events at the London Games in 2012, becoming the
first Chinese man to win Olympic swimming gold.
The 22-year-old has also won five world titles, holds the world
record for 1,500m, and is one of China's best known and
In early 2013 he was suspended from engaging in commercial
activities after missing training and breaching team rules.
Later that year he was ordered to spend a week in a detention center
after crashing a car that he had driven without a license.
China's swimming authorities slapped a blanket suspension on him,
banning him from all training and competition, before he made his
return at the National Championships.
(Refiled to fix headline)
(Writing by Julian Linden; Editing by Peter Rutherford)
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