English marathon runner Paula Radcliffe has admitted that she feels "angry" when people accuse her of doping due to the widespread allegations in the sport.
Last year, claims were made in a German documentary that 99% of Russian athletes took illegal substances, while at least 38 Kenyan athletes are said to have failed drugs tests.
Radcliffe has revealed that due to the concern over doping, her 2:15.25 sec marathon world record has been questioned.
"It's horrible, I get it all the time," The Telegraph quotes Radcliffe as saying. "People say 'she couldn't have run 2-15 clean'.
"I know I can be totally proud but it does make you angry and it does make you think we have to put a system in place that protects those athletes.
"On the one hand you think people can say what they want because you know inside, but it's still not nice to have people saying that."
Radcliffe announced last week that she will end her career at the London Marathon in April.
