The International Olympic Committee's medical commission chairperson, Arne Ljungqvist, has warned athletes at the Winter Olympics in Sochi that if they do not get caught for doping during the Games, then they may still get caught later.
Ljungqvist said that, due to new anti-doping regulations, samples could now be tested within a 10-year period.
There has yet to be any positive doping results in Sochi.
Ljungqvist told reporters: "The message to the athletes [is] that if you cheat, if you take drugs, if we don't find you now we may find you later and we will certainly find you sooner or later. That is an important deterrent message.
"We will exercise that as from now, so these samples that were being collected here will be preserved for 10 more years with a possibility to test them again with new techniques or for substances that we may not have been aware of."
The 2010 Winter Games in Vancouver saw one positive doping test, while there were seven each in the 2002 Games in Salt Lake City and the 2006 Turin Olympics.