The fate of dozens of asylum seekers reportedly being held at sea on an Australian Customs vessel remains unclear, after Immigration Minister Scott Morrison refused to make public any details about the operation.

There have been reports in recent days that two asylum seeker boats have been intercepted by Australian authorities in the Indian Ocean and that the passengers of one of the boats are set to be transferred to the Sri Lankan navy at sea.

• Reports Tamil asylum seekers handed over to Sri Lanka
• Call for information on ‘sick boat people’ 

The ABC understands the boat left the Indian territory of Pondicherry last month with about 150 Tamils on board, but there has been no contact with refugee groups since the weekend.

“You’re making presumptions about instances that I can’t comment on.”

Mr Morrison refused to confirm the existence of the boat and would not address questions about whether the asylum seekers would be handed over to Sri Lankan authorities.

“You’re making presumptions about instances that I can’t comment on,” he said.

Information has been tightly held by the Government under its Operation Sovereign Borders and Mr Morrison says he has no intention of changing that.

Sri Lanka’s High Commissioner to Australia Thisara Samarasinghe told the ABC his government would have no problem with the transfer – although he said he had no knowledge of any such plans.

Opposition Leader Bill Shorten. Photo: Getty

“At sea or whichever the way – if the two governments agree that we could do what is practically possible to achieve the aim of the two governments,” he said.

Federal Labor has stepped up its criticism of Immigration Minister Scott Morrison, accusing him of going into hiding.

“I do not know what is fact and what is fiction when it comes to this Government’s handling of our border security,” Opposition Leader Bill Shorten said.

“Only one person can tell us what’s going on – that’s Scott Morrison. I think it is a disgrace that this Minister isn’t doing his day job and telling Australians what is going on.”

Mothership processing ‘unlawful’: former official

There have also been reports that asylum seekers have been assessed at sea through teleconference.

Asylum Seekers near Christmas Island. Photo: AAP

A former senior immigration official has told the ABC that the idea of processing asylum seekers’ claims at sea had previously been dismissed as unlawful.

Greg Lake, who worked as a manager at the immigration detention centres on Nauru and Christmas Island but quit his job early last year, says the idea of processing asylum seekers on a ‘mothership’ at sea was considered by government agencies in 2012.

He said the proposal involved smaller patrol boats delivering asylum seekers to the bigger ship, which would then move on to Manus Island or Nauru when it was full.

“The advice came back and said that a holding pattern, if you like, where they are waiting [for] further people to fill the boat up, was not lawful,” he said.

“It was a technicality but it had huge practical implications.

“I guess the upshot is the Government has definitely explored, at least (with) the public servants … the possibility of how this could work.”

Abbott says Sri Lanka ‘peaceful’ but ‘not perfect’

Prime Minister Tony Abbott.

Prime Minister Tony Abbott has defended the Government’s approach.

“Everything that we do is consistent with safety at sea and everything that we do is consistent with our international obligations,” he said.

And he has indicated the Government would be comfortable dealing with Sri Lankan authorities, describing the situation in the country which endured more than two decades of civil war up to 2009, as “peaceful”.

“I don’t say it’s a perfect country, not even Australia is that, but it is a peaceful country and all of us should be grateful that the horrific civil war is well and truly over,” he said.

The comments are profoundly concerning for prominent refugee lawyer and director of the Refugee and Immigration Legal Centre, David Manne.

“The fact is that independent, credible sources clearly indicate that human rights abuse is rife across the country [Sri Lanka] and that serious and systematic human rights abuses in Sri Lanka continue to occur on a daily basis,” he told ABC’s The World Today.

“What we need to see here in light of this is that every person individually have (sic) their claims assessed for protection under a fair … process, instead of a blanket assertion that people are under some truncated screening process.”

ABC