Following reports that Russian athletes inhaled xenon to boost their performance at the 2014 Sochi Olympics, the World Anti-Doping Agency has announced it will begin enforcing a new ban on the gas beginning early next week.
The amendment was prompted by what WADA President Sir Craig Reedie called "significant and pressing topics" discussed at a meeting last spring.
Enforcement on other newly banned substances -- including the gas argon -- are also set to begin on Monday.
Last winter, a report from a German broadcaster claimed that Russian team members had been inhaling xenon dating back to the 2004 Athens Olympics.
Russian sports officials subsequently denied that its team had used xenon.
Argon and xenon are elements that are inert gases.