Former 400m world champion could be banned for two years following failed doping test at Glasgow 2014 Commonwealth Games

The B sample taken from Botswana’s Amantle Montsho at the Glasgow 2014 Commonwealth Games has also tested positive for a banned substance, with the sprinter now facing a two-year ban.

The 2011 400m world champion was provisionally suspended after she failed a doping test taken following the 400m final, in which she finished fourth, at the Games on July 29.

She requested for her B sample to be tested and that took place at an accredited laboratory in London on August 4. The Commonwealth Games Federation has confirmed that both samples tested positive for the banned stimulant methylhexaneamine.

Montsho has until August 22 to appeal.

The 31-year-old had gone to the Glasgow Games as the reigning Commonwealth champion, the sprinter having won 400m gold in a Games record time in Delhi in 2010. She won the world title in 2011 and two years later was pipped to gold in Moscow by Britain’s Christine Ohuruogu.

The drug methylhexaneamine has been linked to supplements, causing federations such as UK Anti-Doping and Athletics Australia to release warnings to athletes in 2010. It is present in products available over the counter, including weight-loss aids and energy-boosters.

UK Anti-Doping warned: “There is a risk that supplements could contain this or other prohibited substances even if the ingredients listed on the label do not appear on the World Anti-Doping Code’s Prohibited List.”