Xinhua news agency reports that Chinese Olympic swimming star Sun Yang has finished serving a three-month ban.
He was banned in July, after failing a drug test in May, during China's national swimming championships. Sun tested positive for the stimulant trimeta-zidine, a prescription drug for a particular heart condition.
Trimeta-zidine was added to the World Anti-Doping Agency's banned list in January this year. Sun said he used it for medical reasons, and had been unaware that it was included on the list. Sun has been fined 5,000 yuan, and stripped of the gold medal he’d won during the championships. Sun won the 400 and 15-hundred metre freestyle events at the 2012 London Olympics, and also has five world championship golds to his name.