River Plate duo Camilo Mayada and Lucas Martinez Quarta have failed drugs tests and the latter has been provisionally suspended by CONMEBOL, the Argentine club have confirmed.
A sample provided by Uruguay international Mayada after the Copa Libertadores match against Melgar on May 18 showed positive for the diuretic hydrochlorothiazide.
Martinez Quarta, a 21-year-old midfielder considered close to breaking into the Argentina set-up, was found to have the same substance in his system after the match against Emelec on May 10.
River do not believe the players knowingly used the substance and have requested for their B samples to be analysed.
"Faced with the situation of Camilo Mayada and Lucas Martinez Quarta, the club is working to understand the situation," said an official River statement.
"[The club] vehemently strengthens the assumption of a contamination in some of the products commonly used as supplements."
