Putrajaya, Malaysia - The infamous mattress of the 1998 sodomy trial was brought up again on Monday when Malaysian opposition leader Anwar Ibrahim alleged that his blood was forcibly extracted and smeared on it.

He fingered Inspector-General of Police Tan Sri Musa Hassan, who was then the investigating officer, for ordering police to smear the mattress with his blood, the New Straits Times reported on Tuesday.

The Parti Keadilan Rakyat de facto leader said his evidence on the allegation was a statement made under oath by a forensic doctor during the trial.

Mr Anwar submitted the statement, along with other court documents and statutory declarations from his 1998 sodomy trial, to the Anti-Corruption Agency on Monday to back his claim that Musa and Attorney-General Tan Sri Abdul Gani Patail had fabricated evidence against him.

'I adduced further evidence on how blood was forcibly taken and then spread on the mattress, claimed that it was sperm, and when it was challenged by international experts, they finally withdrew that and amended the charge and the record was expunged,' he said after a three-and-a-half hour session with the ACA on Monday.

'There was evidence by the forensic doctor during the first trial where blood was taken without permission, and this was a statement under oath in court, that the police took it without permission,' Mr Anwar said.

The former deputy prime minister said although his evidence was not new as it was from the previous case, he was trying to show a pattern of deliberate manipulation of evidence.

'The point is, I'm showing a pattern here. I've forgiven them before, but the same pattern is being used in the present case,' he told reporters.

Mr Anwar was accompanied by his lawyers Datuk Param Cumaraswamy and PKR vice-president Sivarasa Rasiah.

It was his second meeting with the ACA after he cut short his first visit last Wednesday before being arrested over sodomy allegations by his former aide Mohd Saiful Bukhari Azlan.

Mr Anwar also welcomed Prime Minister Datuk Seri Abdullah Ahmad Badawi's move to take Mr Musa and Mr Gani off the present sodomy case, but said it was 'one month too late'.

He also reiterated his claim of evidence being manipulated as the reason why he still refuses to give police a fresh DNA sample.

He said his blood had been taken once in 1998 and five times after that until 2004. On all occasions, he said he consented to his blood being taken because of the need to examine his health.

Mr Anwar also said he was 'saddened' by the Kuala Lumpur Hospital director's statement denying that the hospital had forced him to strip naked for his medical check after his arrest last Wednesday.

'I did not say I was forced. But I had to strip naked because they said it was part of the investigations, and my private parts were examined. I had to concede, or otherwise, some of the local media will say that I am not cooperating,' he explained.

He said he filled up a form meant for rape victims before the medical check because he had not seen the police report.