Several World Championship athletes staying at an official team hotel have gastroenteritis.
Alongside German and Canadian athletes, German triple jumper Neele Eckhardt and Botswana's Isaac Makwala fell ill while staying at the Tower Hotel.
Makwala reportedly withdrew from yesterday's 200m heats after suffering with food poisoning.
German athletes due to arrive on Tuesday will be moved to other hotels.
A Local Organising Committee (LOC) statement said: "There have been a number of cases of gastroenteritis reported by team members residing within one of the official team hotels for the World Championships.
"Those affected have been supported by both team and LOC medical staff. In addition we have been working with Public Health England to ensure the situation is managed and contained.As a result, further advice and guidelines have been issued to team doctors and support staff - standard procedure for such an occurrence where a number of teams are occupying championship accommodation."
The Tower Hotel has carried out investigations with environmental health officers and the International Association of Athletics Federations (IAAF) which has shown the hotel was "not the source of the illness".
It said: "We have followed strict hygiene protocol, ensuring that those affected are not in contact with other guests and all public areas have been thoroughly sanitised."
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