Mr Anwar's first trial, which was widely criticised by human rights organisations and independent observers, saw him sentenced to six years in jail for misuse of power.

The BBC's Frances Harrison: "The trial looks set to be more lurid than the first"

The new trial is likely to be as controversial as the first one. and this time the judge has imposed a ban on reporters covering on the proceedings.

If convicted, Mr Anwar could face 20 years in jail and a whipping.

Mr Anwar's brother, Sukma Darmawan, is also on trial, charged with abetting the crime and with committing sodomy himself.

Anwar was found guilty of corruption

In April, Mr Anwar was convicted of four charges of corruption. He currently faces a charge of having committed sodomy with his family's former driver, Azizan Abu Bakar, in May 1992.

Earlier, the courts threw out an appeal by Mr Anwar's adopted brother to have his six-month jail sentence for sodomy revised.

He says that police forced him to confess to sodomy with the former deputy prime minister.

Debate over civil liberties

The trial of Anwar Ibrahim has led to a debate over Malaysia's human rights record under Prime Minister Mahathir Mohamad.

Mr Mahathir has been in office since 1981 and is the longest-serving elected leader in Asia.

Mr Anwar's sacking and consequent arrest in September led to countrywide protests and condemnation by human rights groups.