US Secretary of State Condoleezza Rice on Thursday urged Malaysia to ensure a 'transparent' investigation into sex misconduct allegations against opposition leader Anwar Ibrahim.

Malaysia has accused the United States of meddling in its internal affairs by raising concern over Datuk Seri Anwar's arrest last week on sodomy charges - the same charge that saw him jailed a decade ago.

But Dr Rice defended the stance and said the United States would continue to speak out on cases involving human rights and politics although it did so 'in a spirit of respect for Malaysia'.

'The United States doesn't recognise this very firm barrier that it is simply internal affairs when a case of this kind comes up, but we are going to continue to work with Malaysia', she told reporters.

'One of the things that we have said is that we want to see transparency and for rule of law to be completely followed here'.

Mr Anwar spent a night in custody last week after being arrested by police commandos over accusations that he sodomised a 23-year-old male aide. He was released on bail and must report back to police on August 18.

The events threaten to derail Mr Anwar's spectacular political comeback, after March elections that handed the opposition a third of parliamentary seats. He has said he plans to seize power soon with the help of government defectors.

Anwar was sacked as deputy premier in 1998 and jailed on sodomy and corruption charges widely seen as politically motivated. The sex conviction was overturned by the nation's highest court in 2004.

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