The head of the Olympics has appealed to athletes taking part to stay clean.

It comes as Team Ireland has been dealt a major blow - after an Irish boxer failed a drugs test, ahead of tonight's Olympic opening ceremony in Rio.

23 year old Michael O'Reilly from Clonmel who boxes with a club in Portloaise, was informed of the alleged offence yesterday.

International Olympic Committee president Thomas Bach says dopers have 'nowhere to hide':