South Africa duo Bjorn Basson and Chiliboy Ralepelle are to be sent home from the tour of Britain and Ireland after testing positive for a banned stimulant.
The pair were randomly tested after the Test match against Ireland in Dublin on November 6, with Six Nations Rugby, who administer the November internationals, confirming to the South African Rugby Union that they had tested positive for methylhexaneamine.
Basson was already due to leave the tour because of an ankle injury picked up against Wales on Saturday, but the two players will head for South Africa under different circumstances.
Basson, a 23-year-old winger, won the third of his four caps in the 23-21 win against Ireland and is the record holder for the most tries in a Currie Cup campaign.
Ralepelle is slightly more experienced than Basson, having picked up 17 caps, while he was also the first black player to captain the national side when he led them out against a World XV in Leicester.
The 24-year-old hooker plays his club rugby for the Blue Bulls and came off the bench in Saturday's win over Wales.
Basson started the game against Ireland, while Ralepelle was an unused substitute.
A statement from South Africa Rugby Union confirmed the players had been provisionally suspended from all rugby but could request their 'B' samples be tested.