"Anne Kjersti Kalvå is forced to cancel the Tour de Ski.
She unfortunately tested positive for covid after the race in Oberstdorf yesterday, and traveled home to Trondheim today," the Norwegian Skiing Association writes in a press release.
Kalvå has had a strong tour so far, with third place in the 10 kilometer classic on Wednesday as his main achievement.
Before the three final stages, all in the Italian Val di Fiemme, the Norwegian was third in the overall standings, one minute and 31 seconds behind leader Frida Karlsson.
Previously, a Norwegian leader has also tested positive for covid-19.