An Argentine lawyer, who helped to put his country's former military rulers on trial, has been unanimously elected the first prosecutor of the International Criminal Court (ICC).
Ocampo is currently in private practice in Buenos Aires
The ICC's Assembly of States Parties voted 78-0 for Luis Moreno Ocampo who was the only candidate for the job.
"The experience of Moreno Ocampo... will make him a highly competent and skilled ICC Prosecutor," said David Donat-Cattin of the International Law and Human Rights Programme at Parliamentarians for Global Action.
It is up to Mr Moreno Ocampo now to decide whether or not to launch investigations into any of the more than 200 complaints already received by the body.
The ICC - which was set up by the signatories of the 1998 Rome Treaty - is the first permanent international tribunal established to try cases of war crimes, crimes against humanity and genocide.
The election of an experienced prosecutor... is further proof that the ICC will be a serious, responsible and effective organisation,
Richard Dicker, Human Rights Watch
Eighty-nine countries have signed up to the treaty, which was formally inaugurated in March in The Hague when 18 judges were sworn in.
Eleven countries were not present for the vote at the United Nations' headquarters in New York.
However, the court lacks the support from the United States - a power behind the Nuremberg trials after World War II - which has raised concerns about its potential clout.
Mr Moreno Ocampo helped to prosecute his own country's former military junta in the 1980s.
He is currently in private practice in Buenos Aires, as well as being a visiting law professor at Harvard University in the United States.
Mr Moreno Ocampo was selected by an ICC's committee earlier this year.
"The election of an experienced prosecutor and Harvard professor is further proof that the ICC will be a serious, responsible and effective organisation," Richard Dicker of Human Rights Watch said.