Britain's number one-ranked doubles player Tara Moore has been provisionally suspended under anti-doping rules.
She provided a sample containing substances on the World Anti-Doping Agency (Wada) banned list while competing in Colombia in April.
"I have never knowingly taken a banned substance in my career," Moore said in response to the suspension.
"I am investigating how the positive result could have occurred."
She added: "I look forward to proving that I am a clean athlete. I am deeply saddened by the provisional suspension and hope to be back on the court as soon as possible.