Tyson Gay failed test sample contained a banned steriod

News of the American’s failed test emerged last month, but the details of the substance he tested positive for have – until now – not been made public.

The BBC has obtained extracts of a letter sent to Gay by the United States Anti Doping Agency (Usada) which outlines the nature of the substance traced in a sample he gave to drug testers during the US World Championship trials in June.

The letter, dated 23 July, states: “Using the Carbon Isotope Ratio Analysis it reported that the sample had an adverse analytical finding reflecting values that are consistent with the administration of a steroid of exogenous [external] nature

http://www.bbc.co.uk/sport/0/athletics/23806237

This is a serious one !