United Nations says it has stopped working with disgraced tennis player Maria Sharapova who last week admitted to testing positive for a banned substance. The New York based UN Development Programme, UNDP, said in a statement yesterday that it was suspending Sharapova, who worked as a goodwill Ambassador, until the outcome of the investigation into her case is known. The statement said that the UNDP remains grateful to Maria Sharapova for her support of our work, especially around the Chernobyl nuclear disaster recovery. Last week, the Russian tennis player announced that she tested positive for a drug called meldonium, also known as Mildronate, at the Australian Open earlier this year.