The young man who has accused Anwar Ibrahim of sodomising him faced cross-examination Monday as the Malaysian opposition leader's trial resumed after a lengthy delay.

Anwar, a former deputy premier who was sacked and jailed on separate sex and corruption counts a decade ago, says the allegations have been trumped up to neutralise the threat he poses to the ruling Barisan Nasional coalition.

The trial opened briefly in February with explicit evidence from 24-year-old Mohamad Saiful Bukhari Azlan, who was an aide in Anwar's office, but was suspended as the defence pursued a number of unsuccessful legal manoeuvres.

During his testimony, Saiful had said that Anwar, using vulgar language, propositioned him for sex shortly after he arrived at a Kuala Lumpur apartment on June 26, 2008 to deliver a document.

Prosecutors have said that two days after the alleged incident Saiful underwent a medical examination at a hospital and that DNA tests on samples taken from his body showed traces of Anwar's semen.

Defence counsel Karpal Singh grilled him Monday over how the evidence remained intact, asking whether he had washed before saying Friday prayers the following day, according to Muslim rites.

"I only washed a little, I did not wash my bottom part," Saiful replied, explaining that he did so because he was in an "emergency situation".

Karpal also raised a medical report prepared by one of the doctors who examined him in which he said the young man had complained he was "assaulted with plastic inserted into the anus".

"The doctor is lying," Saiful said, adding that he did not know why he would make up the account.

Asked why another medical report from a different hospital said there was no signs of damage consistent with an assault, Saiful replied: "I do not know as I cannot see my anus."

Pressed further, he said "it's maybe because lubrication was used when I was sodomised."

Anwar's lawyers also grilled Saiful over his meeting with Prime Minister Najib Razak, which he said took place on June 24, two days before the alleged incident.

"I told the then deputy prime minister the problem I was having and did not meet him after that," he said.

Najib has confirmed that Saiful visited him at his home, a meeting that Anwar has said is proof he is the victim of a political conspiracy. The prime minister, who came to power last year, has denied any involvement in the case.

Anwar spent six years in jail on the original sodomy and corruption allegations until the sex conviction was quashed in 2004.

He has reinvented himself as the leader of a reinvigorated opposition which made big electoral gains in 2008 polls, startling the Barisan Nasional which has ruled Malaysia for half a century.

Anwar's lawyers also duelled with the prosecution over access to its witness list which it has refused to provide, along with evidence including medical reports and closed-circuit TV footage.

"In my 40 years of practice, I have not come across such a situation where a prosecutor has refused to supply a list of witnesses," Karpal said.

Human Rights Watch has urged Malaysia to drop the charges against Anwar, condemning the case as a "charade of justice" and saying his lawyers had been blocked from preparing a thorough defence.

Sodomy, even among consenting adults, is illegal in Malaysia -- a conservative and Muslim-majority country. If convicted, Anwar could face up to 20 years imprisonment.

- AFP