Former Chelsea player Deco's positive test for a banned diuretic has been confirmed after the return of his 'B' sample.
The Portugal star, now playing with Brazilian side Fluminense, returned a sample containing traces of the banned furosemide after a match against Boavista last month.
Furosemide can be used to mask other substances.
And now that the returned 'B' sample confirms the original test, the 35-year-old now faces an automatic 30-day stint on the side-lines.
However, Deco has vowed to fight the suspension, with the player's representatives claiming his vitamin supplement was contaminated.
"The first concern for Deco is defending his image and not with any punishment or suspension," Deco spokesman Felleger Ahaz told the O Globo. "He has for a long time taken a vitamin supplement and certainly there has been some contamination."
In a statement on their website, Fluminense said the player had hired his own legal team to represent him in the case while the club were also retaining their own lawyers.
Information from the Press Association was used in this report.