Former world and Commonwealth champion Amantle Montsho has become the second athlete to fail a doping test at Glasgow 2014.
The 31-year-old tested positive for banned stimulant methylhexaneamine after Wednesday night's 400m final at Hampden Park.
The news comes in the same week that Nigerian gold medallist Chika Amalaha was suspended from the Games after also failing a drugs test, with a 'B' sample confirming traces of diuretics and masking agents.
Botswana's Montsho, who finished fourth in the 400m, has yet to have her 'B' sample tested.