Botswana's former world 400m champion Amantle Montsho has failed a drugs test at the Commonwealth Games.
Montsho, who won the world title in 2011 before finishing second behind Christine Ohuruogu last year, tested positive for the banned stimulant methylhexaneamine after the 400m final in Glasgow.
The 31-year-old, who could only finish fourth at Hampden Park last Tuesday, will have her B sample tested today.
Montsho, who is the defending champion, has been provisionally suspended.
A statement from the Commonwealth Games Federation (CGF) read: "In accordance with the CGF anti-doping standard for the XX Commonwealth Games, the CGF federation court conducted a provisional hearing this afternoon to consider an adverse analytical finding submitted by Amantle Montsho of Botswana, after the women's 400 metres final on July 29.
“The athlete’s A sample was found to contain methylhexaneamine, prohibited as a stimulant under class s6 of WADA’s Prohibited List.
“Ms Montsho was notified of her A sample result and has asked for her B sample to be tested, which will take place at the accredited laboratory in London on Monday August 4.”
Montsho is the most high profile athlete to have failed a drugs test at the games, which have also seen 16-year-old Nigerian weightlifter Chika Amalaha stripped of her gold medal.
Montsho finished fourth at London 2012 and was
expected to get on the podium in Glasgow, but was edged out by the Jamaican trio of Stephenie McPherson, Novlene Williams-Mills and Christine Day.
The news about Montsho both surprised and disappointed 400m rival Ohuruogu.“My initial reaction was desperate disappointment, but . . . I need to find out exactly what happened.”