The matter arose during cross-examination of prosecution witness Alias Ali, the Deputy Secretary-General of the prime minister's department. Defence lawyer Christopher Fernando asked if Malaysia's king had consented to the sacking of Mr Anwar, as required by law.

As the trial entered its eighth day Mr Fernando told the court "there was a political conspiracy to bring the trumped-up charges, to remove the accused and to destroy him politically."

But Justice Augustine Paul intervened: "I really can see no bearing between the case and the line you are adopting", he told Mr Fernando.

'Sufficient evidence'

Growing calls for the PM to resign

"Even if you manage to prove there was a conspiracy, my job at the end of the day is to see whether sufficient evidence has been [presented] in relevance to the charge," said Justice Augustine.

Mr Fernando said he was pursuing a legitimate line of questioning. "If you don't allow us to ask these questions, you will deprive us of a fair opportunity to get to the truth," he said.

Since his dismissal on 2 September, Mr Anwar has insisted that charges of corruption and sexual misconduct levelled against him were part of a high level political conspiracy to remove him from government.

The trial has been the focus of unprecedented anti-government demonstrations in Malaysia with growing calls for the resignation of Prime Minister Mahathir Mohamad.

Evidence of conspiracy

Tight security surrounds the trial in central Kuala Lumpur

In a television interview on Tuesday, Dr Mahathir insisted he had been right to dismiss his former deputy from office saying the trial would prove he was "morally unfit" for office.

Last week the outgoing chief of police intelligence testified under cross-examination that a report produced for the prime minister had cleared Mr Anwar of sexual misconduct and found there was evidence of a conspiracy against him.

Mohamad Said Awang, who was the first prosecution witness, also told the court he would commit perjury if told to do so by his superiors or the government.

Unprecedented protests followed Mr Anwar's arrest

Mr Anwar's defence team say missing documents, apparently written by Mr Said, implicate at least two government ministers in a 1997 plot to drive Mr Anwar from office through allegations of sexual misconduct.

Meanwhile in separate developments, Malaysian trade minister, Rafidah Aziz, has warned other governments attending the 21-member Asia-Pacific Economic Cooperation (APEC) forum opening in Kuala Lumpur on Thursday not to raise the issue of Mr Anwar's trial.

The trial itself will be adjourned for the duration of the summit although the American government says Secretary of State Madeleine Albright, who will be attending, plans to make Washington's concern on the issue clear.

Miss Rafidah said she would regard such action as interference in Malaysia's internal affairs.