Rafael Nadal has denied suggestions that he has ever used a banned substance.
Performance-enhancing drugs have been in the headlines this week following Maria Sharapova's announcement that she had failed a drugs test at the Australian Open in January.
Former world number one Nadal has faced accusations before, with former players Olivier Rochus and Daniel Koellerer having both questioned how he is able to recover from injuries so quickly.
Those doubts have resurfaced following the revelation about Sharapova, but a defiant Nadal has insisted that he is a "completely clean guy".
"I have never had the temptation of doing something wrong," the Spaniard told reporters at a press event ahead of Indian Wells.
"I am very far from that, doping. I am a completely clean guy. I worked so hard during my career that when I get injured I never take nothing to be back quicker. I heard it a few times again about doping from my person and I am a little bit tired with that.
"I believe in the sport and the values of the sport. The sport is an example for society. It is an example for the kids and if I am doing something that goes against that, I will be lying to myself, not lying to my opponents."
Fourteen-time Grand Slam winner Nadal is currently ranked fifth in the world.
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