Cape Town - Springbok rugby players Bjorn Basson and Chiliboy Ralepelle will appear before an SA Rugby Union (Saru) judicial committee in Cape Town on Tuesday morning.
The players tested positive for the banned substance, methylhexaneamine, after the first test of the team's Grand Slam tour against Ireland in Dublin in November. Both were immediately sent home. Their 'B samples' later also tested positive.
They were suspended under International Rugby Board rules, and were banned from all rugby activities until the matter was resolved.
Neither contested the testing procedure, which allowed the investigation and hearing to take place in South Africa.
Methylhexaneamine, which can be used as a nasal decongestant, and is found in nutritional supplements, was added to the World Anti-Doping Agency's list of banned substances last year.
Both players reportedly denied knowingly taken the substance.
South African officials said they believed a nutritional supplement taken by all the players during the five-week tour may have caused the positive tests, and its usage is likely to be reviewed during the investigation.
The hearing, which will be conducted by a three-man committee selected by Saru, starts at 09:00 on Tuesday.