Azizan Abu Bakar told the court that everything he said in a sworn statement made on 5 August 1997 - when Anwar was still deputy prime minister and finance minister - was true.
Mr Azizan, 38, was asked to read from the statement. "In the name of Allah... I have become a victim of homosexual acts by Anwar Ibrahim, who now holds the position of deputy prime minister," he read to a stunned courtroom. "This heinous act was committed several times in 1992 against my will. It regularly took place in luxury hotels... without the knowledge of the public and his wife."
Mr Azizan was the driver for Mr Anwar's wife, Azizah Ismail, from 1989 to 1992. He is now a sales executive in a trading company. "I had on several occasions tried to resist," Mr Azizan continued. "His chronic behaviour caused me great mental stress. The feeling of guilt finally overcame me whenever I had to gaze on Azizah, who had such high moral character. Finally, I made the decision to stop from becoming a homosexual slave to this man, Anwar Ibrahim, whom I regard as an animal."
Sodomy is a crime in this predominantly Muslim country.
Mr Anwar showed no reaction during the graphic testimony. During the lunch break he hugged his daughter while his wife looked on solemnly.
He faces four counts of abuse of office, and will face trial later for one more charge of corruption and five counts of illegal sexual acts. He denies the charges, calling them part of a high-level conspiracy.
The Prime Minister, Mahathir Mohamad, fired Mr Anwar on 2 September, saying he had conducted his own investigation and had determined Mr Anwar was morally unfit for office.
Earlier, witnesses for the prosecution - high-level police and intelligence officers - testified that Mr Anwar abused his power by forcing police to get a retraction from Mr Azizan.
Although Mr Anwar secured a retraction, which was forwarded to Mr Mahathir, Mr Azizan testified yesterday that he stood by his original statement.
Earlier in the day, the court proceedings came to a temporary halt when the judge, Augustine Paul, turned his attention to a second defence lawyer who accused prosecutors of fabricating evidence against Mr Anwar.
Manjeet Singh Dhillon, charged with contempt of court, represents Mr Anwar's former tennis partner, Nallakaruppan Solaimalai. Nalla, as he is called, is charged with possession of ammunition, which carries a death sentence.
On Monday, a warrant was issued by the court for Mr Manjeet Singh after he wrote a letter accusing prosecutors of trying to force Nalla into a plea bargain by giving false evidence against Mr Anwar about alleged sexual trysts. Mr Manjeet Singh quickly apologised yesterday. Mr Paul accepted the apology and resumed the trial, now in its fourth week. (AP)