Chinese 110m hurdler Liu Xiang has announced his retirement at the age of 31.
Liu won the gold medal at the 2004 Athens Games, which was his country's first ever Olympic gold in track and field.
A hugely popular figure in China, his career was also hindered by a series of injury setbacks.
Liu was forced out of the first heat at the 2008 Beijing Games, while he also suffered an early exit at London 2012.
"From today, I will end my life as a professional athlete and retire formally," he said in a statement. "This is a decision made after long deliberation. I am deeply reluctant and feel pained, but I have no choice."
Liu also won gold at the 2007 World Championships and the 2008 World Indoor Championships.
