CANBERRA, May 28 (IPS) - Months after a row erupted over the Australian government's role in the 2001 sinking of a boat carrying asylum seekers from Indonesia, a government minister and the head of the Australian Federal Police (AFP) have refused to discuss crucial details of what was known about the ill-fated voyage.

In an often fiery hearing of the Senate legal and constitutional committee on Tuesday night, AFP Commissioner Mick Keelty and Justice Minister Sen Chris Ellison invoked 'public interest immunity' rather than answer critical questions about their knowledge of the boat's voyage.

Codenamed SIEV-X by the Australian military, the boat sank on Oct. 19, 2001 in international waters off Australia's northern coast, resulting in the drowning of 353 mostly Iraqi and Afghan asylum seekers.

The Australian government has persistently claimed it had no prior knowledge of the location, time of departure or where the SIEV-X sank.

However, ever since the tragedy occurred in the midst of an election campaign in which Prime Minister John Howard openly villified asylum seekers, nagging questions have persisted about a shadowy multi- million dollar campaign that was being run by the Australian Federal Police in Indonesia to 'disrupt' people-smuggling operations.

On Tuesday night, the leader of the opposition in the Senate, Sen John Faulkner, asked whether tracking devices, which would have enabled detailed knowledge of the boat's location and sinking, were placed on SIEV-X by AFP officers in the process of tracking the vessel bound for Australia.

Keelty said there was no tracking device 'from the AFP's knowledge' placed on the ill-fated boat.

Such a device would have provided Indonesian and Australian agents working on the 'disruption' programme with precise information on where the boat was when it departed and enabled prompt rescue when it sank.

Asked if such devices were placed on it by Indonesian officials but with the knowledge of the AFP, Keelty was less certain: 'That is not something within my knowledge.'

When Faulkner asked whether tracking devices had been placed on the SIEV-X by Indonesian officials at the request of and supplied by the AFP, Ellison exploded. 'I'm not taking that on notice. I'm saying that we won't answer it... on the basis of public interest immunity and that it goes to operational matters,' he angrily told the committee.

The release in February 2003 of a previously secret diplomatic cable - which the Australian Embassy sent the day after the sinking became public knowledge -- revealed that government officials were aware of where and when the boat had departed and the time and approximate location of its sinking.

The cable tellingly revealed that there had been radio communication between the SIEV-X after it departed and the man who has admitted organising the voyage, Egyptian-born Abu Quessay.

Ellison vigorously defended the AFP's answers to written questions that claimed they had no knowledge of 'distress calls' from the doomed boat, when Labor Party Sen Jacinta Collins had asked about 'radio communications' in general.

'I am concerned that the AFP still seems to be attempting to reframe my question in the most limited form to justify why a fulsome answer wasn't given now that we are aware of the information (about radio communications) that came forward in the cable,' she said.

Ellison also would not allow questions about whether the SIEV-X survivors were shown what appeared to be surveillance photos of their boat by Indonesian police looking into the case.

Former Australian diplomat Tony Kevin, who has doggedly pressed for an inquiry into what the Australian government knew about the fate of the SIEV-X, believes the government is increasing worried about the precise questioning it has been subject to.

'When it suits them to make a specific denial they make it, but when it is a general question about what are the ground rules of what they do and don't do, they say, 'we can't answer that question',' he said.

In late April 2003, Indonesian Justice Minister Yusril Ihaza Mahendra refused to deport Quessay to Australia in relation to the case, claiming that Canberra was not serious about prosecuting him for the deaths of those aboard the SIEV-X.

Instead, the Indonesian government deported Quessay to Egypt, where he has been remanded in custody until Jun. 15 pending decisions on charges and a request by Ellison that he be extradited to Australia.

However, on Friday Justice Minister Ellison announced that Swedish authorities had arrested Khaleed Daoed, an alleged accomplice of Quessay in organising the journey of the SIEV-X. According to interviews with survivors, Daoed's role was negotiating the cost of a place on the boat with potential passengers.

Australia has an extradition treaty with Sweden which -- depending on the decision of the courts -- should make Daoed's deportation to Australia reasonably straightforward. But the prospects of Quessay ever facing trial in Australia are slim.

Kevin welcomes Daoed's arrest but worries about the Howard government's continued refusal to answer important questions before government bodies inquiring into the sinking of the asylum seekers' boat.

'I'm very pleasantly surprised by the arrest. I wasn't expecting it, but I want to see now whether it is a genuine process or whether it is just more smoke and mirrors to create an appearance of doing something while Senate committees are sitting,' Kevin said.