Nine-time Olympic gold medalist Usain Bolt will have to return one of his medals after one of his Jamaican team mates tested positive for a banned substance. Nesta Carter, the team mate in question, was part of the 4x100 team that won gold in Beijing 2008. The team also contained Asafa Powell and Michael Frater.

Retrospective testing

The International Olympic Committee (IOC) regularly test random doping samples from previous Olympics. The IOC re-test urine samples in order to detect whether athletes used substances that prevent performance enhancing drugs appearing on doping tests in the short term.

Nesta Carter's sample was found to contain methylhexaneamine, a stimulant that has an energy boosting effect on the user.

Originally sold as nasal decongestant in the United States, at least five deaths have been associated with dietary supplements that contain methylhexaneamine. The stimulant was banned by the IOC in 2006.

Nesta Carter also ran the first leg in the 4x100 event at the London Olympics in 2012. Jamaica won the gold in 2012, too. Carter was part of the Jamaican teams that won gold at the World Championships in 2011, 2013 and 2015.

Tatiana Lebedeva, who represented Russia at the 2008 Beijing Olympics, was stripped of her long jump and triple jump medals for testing positive for dehydrochlormethyltestosterone.

Usain Bolt told the Jamaican Gleaner: 'It is incredibly heartbreaking. For years we have worked hard to accumulate medals and represent our country. It's one of those things. I'm more concerned about Nesta, I hope that he is able to get through it'.

Roger Black, a two time silver medalist from Britain, said: 'It is really frustrating for him [Bolt].

It will not damage his glistening reputation as the greatest of all time but he wont be happy. However, when I hear stories such as this I celebrate. With retrospective testing, athletes can never sleep peacefully'.

What happens next?

Trinidad and Tobago and Japan, who finished second and third in 2008, will now be presented with the gold and silver medals respectively. Brazil, who finished fourth, will now be presented with the bronze medal.