Florence Hartmann had faced a possible seven years in prison
Florence Hartmann - who has has been fined 7,000 euros (£6,100) for disclosing confidential documents from the International Criminal Tribunal for the Former Yugoslavia in The Hague - was the war crimes court's official spokeswoman for six years.
As such, the Frenchwoman, 46, had access to documents detailing Serbian government involvement in the Bosnian war of the 1990s.
As a journalist, Hartmann had been covering the Balkans since 1987, writing for the French daily Le Monde from Belgrade before taking up her role at the ICTY in 2000.
When she left her post as spokeswoman for the former chief war crimes prosecutor Carla del Ponte in 2006, Hartmann published a book - Peace and Punishment - and a subsequent magazine article for the Bosnian Institute detailing confidential court documents.
She wrote that the court had decided in secret not to disclose information that could have proved a link between Belgrade and war crimes committed in Bosnia - most notably the massacre of up to 8,000 Muslim men and boys at the Bosnian village of Srebrenica in 1995.
Serbia had given the court these documents during the war crimes case against former President Slobodan Milosevic, on the condition that they be kept secret.
That trial ended without a verdict when Milosevic died at The Hague in March 2006. The original documents are still not in the public domain.
Some analysts say such papers might have helped Bosnia in its failed attempts to sue Serbia for genocide.
Critics say the documents should never have been the subject of a confidentiality order in the first place, and have called the case against Hartmann an attack on free speech.
But the court's backers say the case will help uphold its credibility, and that by publishing confidential documents, Hartmann jeopardised future trials.
They argue the war crimes court must show it is willing to enforce confidentiality agreements, otherwise states will never lend potentially sensitive documents in future cases.
Sentencing her on Monday, Judge Bakone Moloto said Hartmann had "knowingly and wilfully interfered with the administration of justice" by revealing the court documents.
Hartmann was found guilty on two charges of contempt, for which she could have faced a maximum sentence of seven years in prison.
While the judge accepted the defence's argument that some of the information had been disclosed by other journalists before Hartmann, he said there was a need to deter wrongful disclosure of confidential information in the future.
As a Balkans correspondent in the early 1990s, Hartmann had written about the discovery of a mass grave containing the remains of more than 200 people in Ovcara, Croatia.
She gave evidence in 2006 before the ICTY in a case against three Yugoslav army officers accused of involvement in the mass killing.