UEFA has banned Ajax Amsterdam and Cameroun goalkeeper Andre Onana for 12 months for a doping violation.
According to a club statement, the substance Furosemide was found in Onana's urine sample following a drugs test on October 30 last year.
The suspension is effective from today and applies to all football activities, both national and international.
According to the club, the Camerounian keeper mistakenly took his wife's medicine after he felt unwell on October 30 last year.
"On the morning of October 30, Onana was feeling unwell. He wanted to take a pill to ease the discomfort. Unknowingly, however, he took Lasimac, a drug that his wife had previously been prescribed. Onana’s confusion resulted in him mistakenly taking his wife's medicine, ultimately causing this measure to be taken by UEFA against the goalkeeper," the statement said.
"Furthermore, the disciplinary body of the football association has stated that Onana had no intention of cheating. However, the European Football Association believes, on the basis of the applicable anti-doping rules, that an athlete has a duty at all times to ensure that no banned substances enter the body".
Onana and Ajax intend to appeal the decision at the Court of Arbitration for Sport (CAS).
Managing director of Ajax Edwin van der Sar said: “We explicitly renounce performance-enhancing drugs, we obviously stand for a clean sport. This is a terrible setback, for Andre himself but certainly also for us as a club. Andre is a top goalkeeper, who has proven his worth for Ajax for years and is very popular with the fans. We had hoped for a conditional suspension or for a suspension much shorter than these twelve months, because it was arguably not intended to strengthen his body and thus improve his performance.”
In a separate statement, Onana said he mistook the medicine for aspirin because the packaging was almost identical.
He added that although he respects UEFA's decision he considers the verdict excessive and disproportionate for an unintentional mistake.
He said: "I mistook a medicine containing a substance banned by WADA for a simple aspirin. The medicine was prescribed to my girlfriend and I mistakenly took it for an aspirin because the packaging was almost identical, which I greatly regret.
"I have to say that I respect the UEFA Appeals Body, but I do not share their decision in this case. I consider it excessive and disproportionate as it has been acknowledged by UEFA that it was an unintentional mistake. Everyone knows that I lead a very healthy life, and since I started my sporting career, I have always been strongly against any use of doping and I condemn any unsportsmanlike conduct. I am 24 years old and during the last few seasons I have been lucky enough to play almost every minute, both for Ajax and for my national team, being named the best goalkeeper in Holland for the last four years and in Africa for the last three years. I want to say that I have no need to resort to doping to further enhance my sporting career.
"I will appeal the decision before the Court of Arbitration for Sport (CAS) to prove my innocence and clear my name. I hope to be back on the pitch soon to do what I love and help my teammates. I would like to thank Ajax and the Cameroon national team for their support and confidence in me".