The IOC said the athlete, who did not win a medal, was disqualified from those Games and all events she competed in, along with the entire 4x6km relay team of which she was part.
Gergorin's best finish was fifth in the 12.5km mass start.
"The re-analysis... followed an intelligence-gathering and risk-assessment process that started in January 2017," the IOC said in a statement.
"The process is now completed, ahead of the statute of limitations for the samples collected, expiring in February 2018."
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The IOC regularly re-tests samples of past Games in order to catch cheats using new methods of detection of banned substances or testing for ones that were not known at the time of the competition.
Re-tests from the Sochi 2014 winter Olympics, triggered by allegations of systematic doping and tampering of samples of Russian athletes, led to the ban of Russia from next year's winter Games in Pyeongchang, South Korea.
Russians who are cleared to compete will do so as independent athletes under the Olympic flag.
(Reporting by Karolos Grohmann; Editing by Christian Radnedege)
