The IAAF has defended its decision to ban Isaac Makwala from competing at the World Championships.
The Botswana athlete was denied entry to the stadium for last night’s 400 metres final on medical grounds following a bout of norovirus.
The IAAF say: “The athlete was diagnosed with an infectious disease on Monday.
“As per UK health regulations, it was requested that he be quarantined in his room for 48 hours, a period which ends at 14:00hrs on Wednesday"
Makwala insists he wasn't sick and has accused the games' governing body of "sabotage".
Pam Venning, head of medical at the IAAF, told BBC Sport: "I have to trust my doctors. My role is to ensure the healthcare of all the athletes here and it's a very infectious and very virulent disease."
In a later statement, the governing body said:
"The team doctor, team leader and team physio had been informed following the medical examination that the athlete should be quarantined for 48 hours and would therefore be missing the 400m final on Tuesday."