Shawn Crawford, the 2004 Olympic 200m gold medallist, has been banned for two years for failing to give anti-doping officials his whereabouts for testing, the US Anti-Doping Agency said Thursday. The 35-year-old Californian was part of the USADA National Testing Pool from 2001 through the beginning of 2013, and was required to provide his whereabouts for out-of-competition testing, but failed to do so three times in an 18-month span, USADA said. bb/gph

Cycling's global governing body the UCI on Thursday announced that Russian rider Valery Kaykov had been suspended provisionally after failing an out-of-competition doping test. The UCI said that it acted after a lab in the German city of Cologne, accredited by the World Anti-Doping Agency, found that an A-sample of Kaykov's urine contained GW1516 sulfone. The substance was found in a test conducted on March 17 and is a so-called metabolic modulator -- which helps boost the production of hormones which can enhance an athlete's performance.

The rate of positive doping tests in South Korean sports reached a four-year low in 2012, the country's top anti-doping body said Tuesday. The Korea Anti-Doping Agency said it conducted 2,830 tests last year and 15 athletes tested positive for illegal substances. The KADA said it tested "B" samples for some athletes to confirm their doping. The positive test rate for 2012 came to 0.53 percent, the lowest since 0.49 percent in 2008.

World athletics championships hosts Russia on Monday rejected claims they are soft on doping, saying the exposure of a spate of high-profile cheats was due to a step forward in testing. A number of Russian athletes, including 2004 Olympic hammer champion Olga Kuzenkova, have been banned in recent months for doping violations, prompting calls in some quarters for Moscow to be stripped of its right to host the championships later this year.