United Nations - The United Nations has suspended Maria Sharapova as a goodwill ambassador after she failed a drug test at the Australian Open, the latest fall from grace for the Russian tennis star.

Russian tennis player Maria Sharapova speaks at a press conference in Los Angeles on March 7, 2016. [Photo/Agencies]

Sharapova had been a goodwill ambassador for the UN Development Programme for the past nine years, and had been active in helping recovery efforts after the 1986 Chernobyl disaster.

"The United Nations Development Programme remains grateful to Maria Sharapova for her support of our work, especially around the Chernobyl nuclear disaster recovery," said a spokesman

"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."

"We wish Ms. Sharapova the best," she added.

Former world number one Sharapova announced last week that she failed a drug test at the Australian Open in January.

Sharapova tested positive for meldonium, which was added to the World Anti-Doping Agency's banned list on January 1.

US sportswear giant Nike, German luxury car maker Porsche and Swiss watchmaker TAG Heuer have all halted their relationship with the former world number one.

Sharapova has made visits to Belarus as goodwill ambassador and donated $100,000 to support youth projects in rural areas that suffer from the after-affects of the Chernobyl nuclear accident.

Sharapova's family fled the city of Gomel in Belarus in 1987 after the Chernobyl disaster, moving to Siberia where the tennis star was born.

The family lived in Nyagan, Siberia for two years and then moved to Sochi on the Black Sea where Sharapova took her first tennis lessons.