Former Deputy Prime Minister Anwar Ibrahim says Dr Mahathir made slanderous comments about his sexual behaviour at a press conference on 22 September.

The offending comments were then published in Malaysia's Sun newspaper under the headline," Anwar's behaviour despicable: PM".

According to Mr Anwar, the accusations were repeated in Newsweek - a US-based publication with an international circulation, and were also televised widely by CNN International and other broadcasters.

Mr Anwar says their publication did grave injury to his character, credit and reputation both nationally and internationally.

Frank account

The allegedly defamatory statements involved graphic accounts of Mr Anwar's alleged acts of sodomy, which is a crime in Malaysia.

Anwar Ibrahim's trial has promted a wave of protests against Dr Mahathir

Dr Mahathir said that he spoke with an "honest belief in the truth" and that his statements "were not made recklessly, without disregard for the truth or untruth of the words."

In his defence, Dr Mahathir said that the alleged defamatory words were published in his capacity as prime minister and that he wanted to make his reasons for dismissing Mr Anwar known.

He contends that Mr Anwar was not entitled to any damages and is asking the court to dismiss the suit.

Mr Anwar is also suing Sun Media Corporation, the publishers of the Malaysian Sun, for $25m.

Anwar trial ends

Mr Anwar has been standing trial on four charges relating to corruption and abuse of office.

He is accused of abusing his power to cover up sexual misconduct and has also been charged on a further five counts of engaging in illegal sex.

His corruption trial drew to a close on Thursday and a verdict is due on 14 April.