A member of the far-right Golden Dawn party will represent Greece on the Council of Europe’s Committee on Equality and Non-Discrimination.
The appointment of Eleni Zaroulia, the wife of Golden Dawn’s party chairman, has been condemned by members of the Anti-Defamation League (ADL).
Members of the Golden Dawn party, known for its xenophobic and racist rhetoric, have committed violent acts against immigrants and ethnic minorities living in Greece.
Abraham Foxman, director of the ADL, said: "The despicable ideology of Golden Dawn stands in the most stark contrast imaginable to the goals of the Committee on Equality and Non-Discrimination.
"Given the party's rhetoric, it is an affront to concepts of equality and non-discrimination that one of its representatives now serves as a member on this Committee."
Mrs Zaroulia was appointed to the non-discrimination body on October 1.
Mr Foxman continued: "We urge you to take this step before any further harm is caused by the presence of a Golden Dawn representative on your Committee.
"If a procedure is available to remove her from the committee, such action would demonstrate that commitment to the committee's mandate starts at home."