MOSCOW -- A top Russian skateboarder has received a four-year doping ban, just as his sport prepares to make its Olympic debut.
The Russian Anti-Doping Agency says Maxim Kruglov, known as "Mad Maxim," was punished under a rule against athletes who evade or refuse giving a drug-test sample.
The agency didn't give further details of Kruglov's actions.
Kruglov was the top-ranked Russian in the World Cup street series last year and was aiming for a place at next year's Olympics in Tokyo. However, he told Russian sports website Championat last year he clashed with the Russian Skateboarding Federation and was skating independently of its national team.