South Africa's Olympic bronze medalist Henri Schoeman faces allegations of doping during the 2016 Rio Olympics.
The International Triathlon Union (ITU) has launched an investigation into allegations that Schoeman failed a doping test at the Rio Games.
It's alleged that the 27-year-old tested positive for the banned glucocorticoid prednisolone during the Games.
This emerged after Russian hacking group Fancy Bears leaked internal emails between Olympic staff.
Schoeman is apparently co-operating with investigations.
Sports scientist Dr Ross Tucker has had access to the leaked documents and explores the mystery.
He says that athletes are required to declare any drugs taken seven days ahead of the Olympics.
Curiously, Schoeman declared that he had taken the prednisone drug a month before the Games, Dr Tucker explains.
There is no evidence that indicates Schoeman had a applied for a medical exemption, known as a therapeutic use exemption (TUE).
Dr Tucker says TUE are often back-dated to cover up alleged doping. He says the email records may raise suspicions of a cover-up.
The sports scientist says that an allegation like this will undoubtedly damage Schoeman's career and credibility.
When athletes are dope tested they have to fill out a form as part of doping control in which they declare any medication that they've taken.— Dr Ross Tucker, Sports Scientist at The Science of Sport
On that form, Henri Schoeman declared that he was using a substance called prednisone. The substance that was found in his urine was prednisolone.— Dr Ross Tucker, Sports Scientist at The Science of Sport
Prednisone is an anti-inflammatory steroid hormone to treat conditions like allergies, repository infections and skin conditions. We don't know which condition he had in order to be given this drug,— Dr Ross Tucker, Sports Scientist at The Science of Sport
He was given the prescription on the 17th of July, which is one month before the Olympic Games.— Dr Ross Tucker, Sports Scientist at The Science of Sport
This is a drug that the athlete can take outside of competition. It's not illegal to take when he's not competing.— Dr Ross Tucker, Sports Scientist at The Science of Sport
If, however, the athlete is in competition and they have similar drug in their system, then it is a doping effect.— Dr Ross Tucker, Sports Scientist at The Science of Sport
Take a listen to the allegations: