OSLO: Norwegian cross country skier Therese Johaug, a seven-time world champion and former Olympic gold medallist, has failed a drug test, the Norwegian ski federation announced on Thursday (Friday in Manila). The 28-year-old tested positive for traces of the banned anabolic steroid clostebol during an out-of-competition control on September 16. Johaug won relay gold at the 2010 Vancouver Olympics and silver in the 30km freestyle and bronze in the 10km classical in Sochi 2014. The federation said the skier was unaware that the substance was contained in a lip cream called Trofodermin she used to treat burns during a training session at altitude in Italy late August. National skiing team doctor Fredrik Bendiksen took responsibility and announced later Thursday his immediate resignation.