Maria Sharapova has been suspended from her role as a United Nations Goodwill Ambassador following her failed drug test.
The 28-year-old tested positive for meldonium at the Australian Open and has been provisionally suspended from tennis pending an independent tribunal ruling on the case.
Sharapova was appointed to the role with the UN Development Programme in 2007, with a special focus on helping with the recovery efforts after the 1986 Chernobyl nuclear disaster.
A UNDP spokeswoman said: "The United Nations Development Programme remains grateful to Maria Sharapova for her support of our work, especially around the Chernobyl nuclear disaster recovery.
"However, in light of Ms Sharapova's recent announcement, we last week suspended her role as a Goodwill Ambassador and any planned activities while the investigation continues."
Sharapova's family fled the Belarusian city of Gomel for Siberia the year before she was born because of concerns about radiation in the wake of the Chernobyl disaster.
After signing on for a symbolic one US dollar, Sharapova described the UNDP role as "one of my proudest contracts ever" and announced she would donate €100,000 to eight Chernobyl-related projects.
Sharapova's commercial partners have had differing reactions to her positive test.
Nike, Porsche and Tag Heuer distanced themselves but the Russian's racket sponsor Head has been a vocal supporter.