While the DOSB (the German Olympic Sports Confederation) has not yet revealed the identity of the athlete, German news agencies have named double Olympic cross-country gold medallist Sachenbacher-Stehle as the one in question.

Sachenbacher-Stehle, 33, has won five Olympic medals in cross country, and just missed out on her first in biathlon when she finished fourth in the 12.5 km mass start race on Monday. At the start of the 2006 Winter Olympics in Turin, her fourth Games, she had received a five-day suspension at the start due to a high haemoglobin level.

The DOSB said it had been informed by the International Olympic Committee (IOC) on Thursday evening that an A sample of a doping test on a member of the German team showed an abnormal reading. It added a B sample of the test would be opened late Friday.

The team's chef de mission, Michael Vesper, would provide further information afterwards, the statement said.

A spokesperson for the IOC, Emmanuelle Moreau, said it was "not in a position to comment."

"We have a strict procedure in place and, as a general rule, we will only communicate when a process is completed and a decision is reached," Moreau added.

Hermann Weinbuch, the German combined winter sports trainer, said: "I am totally shocked."

Germany is currently ranked third in the standings with 16 medals, including eight golds.

Ahead of the Olympics, the IOC announced it was planning to carry out 2,453 tests during the Games, including 1,269 pre-competition controls in order to prevent cheats from reaching competition.

If the doping is confirmed with the B sample, it would be the first case of doping at the 2014 Games.

hc, ph/ipj (Reuters, dpa, SID)