Scottish 800m runner Lynsey Sharp has claimed that there are plenty of athletes "getting away" with taking illegal performance-enhancing drugs.
The 22-year-old was handed a gold medal following last June's 800m final in Helsinki, but only because she was upgraded due to Yelena Arzhakova being tested positive for drugs.
"It's a huge problem," Sharp told BBC Scotland. "There's a lot of people being caught, but it's nothing compared to the amount of people getting away with it. If you spoke to any athlete, they would say there's a lot of people who get away with it and probably don't get caught.
"I'm trying to see the positives, but at the same time you're thinking 'what's the point?' in this if this sort of thing happens. It's so disappointing that it's still an issue in the sport. The 800m in particular is pretty bad for it, it's depressing."
Arzhakova was stripped of her gold medal after an "abnormal haemoglobin profile in her biological passport" was found.