11 November 2013
Last updated at 16:57 GMT
By David Bond
BBC sports editor

Jamaica's most senior drug tester says the country's recent rash of failed tests might be the "tip of an iceberg".

Dr Paul Wright told the BBC that up to now the Caribbean island's anti-doping regime had been woefully short of the international standards required.

His comments come a week after the World Anti-Doping Agency visited Jamaica to investigate claims that the country's athletes were not being tested rigorously enough.

Former Jamaican Anti-Doping Commission executive director Renee Anne Shirley sparked the crisis when she said the agency conducted just one out-of-competition test in the six months leading up to the London Olympics.