Indonesian prosecutors' bid to link cleric Abu Bakar Bashir to Jemaah Islamiyah took a step forward when a confessed senior member of the extremist group identified the elderly preacher as its leader.

Mohammad Nasir Abbas, a Malaysian former Jemaah Islamiyah regional commander convicted for immigration offences, told Bashir's trial that he had been informed of the 66-year-old's appointment by another key militant in 2000.

Bashir is accused of leading the extremist group, said to have links to Al-Qaeda, and of inciting followers to carry out the October 2002 Bali attacks in which 202 died and a deadly blast last year on Jakarta's Marriott hotel. If convicted he faces a possible death sentence.

Efforts to link him to the group, blamed for other attacks in Indonesia including a recent strike on Australia's embassy, have suffered setbacks as a series of earlier statements from convicted militants all denied Bashir's role.

Abbas told the trial in Jakarta that he had been informed by fellow Jemaah Islamiyah operative Hambali at a militant camp in the Philippines that Bashir had taken over as head after the death of his predecessor, Abdullah Sungkar.

He said he then passed the information on to another member of the organisation, Mustofa, alias Imron Baehaqi. "After I heard it from Hambali, I told Ustadz [teacher] Mustofa that the Emir of the Jemaah Islamiyah has now been replaced by ustadz Abu Bakar Bashir," Abbas told the court.

Abbas said he had believed Hambali's statement. "Among fellow JI members, we have a tradition of mutual faith in what the other says," Abbas said.

Last week Baehaqi denied before the same court that he had seen Bashir at the Philippine training camp and said he could not confirm the religious teacher was head of Jemaah Islamiyah.

Five other witnesses were scheduled to make an appearance at Bashir's trial on Tuesday, but three declined to attend.

Convicted Bali bombers Ali Imron and Mubarak both said in a letter read out in court, that they had already testified on Bashir during the cleric's trial last year and that "there are no new matters," to inform the court. A Balinese witness, Putu Eka Mastawan, declined to testify saying business commitments prevented him leaving the resort island.

Bashir was cleared last year by an Indonesian court of leading Jemaah Islamiyah, which seeks to create an Islamic fundamentalist state in Southeast Asia, but police say they have new evidence of his leadership role.

The cleric was arrested a week after the Bali blasts and has remained in detention ever since. Prosecutors have said in their indictment that he orchestrated the Marriott bombing from his cell.

Bashir has described the indictment as "legal fiction" and said he had nothing to gain from acts of terrorism since they would only fuel interference in Indonesia by Washington.

Foreign governments, which view Bashir as a major threat, are keen for a conviction in the trial which is seen as a test of new President Susilo Bambang Yudhoyono's commitment to tackling extremism in his country.

Indonesia has been placed on high alert in the days before Christmas following warnings by Australia, Britain and the United States that militants are plotting a new attack.