Sydney - The Australian government apologised unreservedly to Jakarta on Friday after its navy "inadvertently" violated Indonesian waters during border security operations, but vowed to pursue its policies to halt asylum-seeker boats.
Asylum-seekers arriving on unauthorised boats in Australia, often via Indonesia, are a sensitive issue for both sides, and Canberra's military-led Operation Sovereign Borders to clamp down on them has raised concerns in Jakarta.
"We deeply regret these events," Immigration Minister Scott Morrison told a press conference before issuing a statement declaring the hardline stance had resulted in no single arrival for more than four weeks.
Foreign Minister Julie Bishop on Thursday night offered her Indonesian counterpart Marty Natalegawa "an unqualified apology on behalf of the Australian government for inadvertently entering Indonesia's territorial waters", Morrison said.
With Canberra's vital relationship with Jakarta already strained over spying allegations, she also gave "an assurance that such a breach of Indonesian territorial waters would not re-occur".
Morrison said the government learnt on Wednesday that the Australians had entered Indonesian waters on several occasions.
"I should stress this occurred unintentionally and without knowledge or sanction by the Australian government," he said.
Lieutenant General Angus Campbell, who heads the operation to stop asylum-seekers arriving in Australia by sea, refused to detail what the vessels were doing for "operational reasons".
But the Australian newspaper reported the navy had been pushing back an asylum-seeker boat at the time.
Under the new government's policy, not only are asylum-seekers arriving by boat sent to Pacific island camps for processing with no chance of settlement in Australia, but boats intercepted at sea can be turned back to Indonesia.
The policy angers Jakarta which has suggested it could infringe the country's sovereignty and the issue has strained relations between the nations.
Agus Barnas, spokesperson for Indonesian co-ordinating minister for political, legal and security affairs Djoko Suyanto, said on Friday he did not have any details about the territorial breaches.
But he went on: "If they enter our waters without our permission, of course that could worsen our bilateral relations.
"It could interrupt the normalisation process going on between Australia and Indonesia. Australia should fully respect Indonesia, and if they have entered our waters, that could be seen as a breach of our sovereignty."
Morrison insisted there would be no change in Australia's policy, which has been characterised by a near blackout on events at sea.
"Despite the unintentional entry of Australian border protection assets into Indonesian territorial waters, our operations that are stopping the boats will continue," he said in a statement.
"There will be no change of policy. We will simply be making sure that there will be full operational compliance with our policies to stop the boats."
With no-one who has arrived illegally by boat being transferred to Australian immigration authorities since 19 December, it was the first time in more than five years that no asylum-seekers had arrived at this time of the year, he added.
Arrivals have fallen more than 80% since the Liberal-National government won power in September.
Australia's military chief of staff and the head of border protection would front a review of the violations, Morrison said, as reports emerged that the navy had started using lifeboats to return asylum-seekers to Indonesia.
The Sydney Morning Herald detailed allegations from asylum-seekers now back in Indonesia that the navy had tricked 56 of them into boarding a lifeboat in the belief they were being taken to Australia's Christmas Island.
A group of the would-be refugees from South Asia told the daily they scuttled their vessel last week in a bid to avoid going back.
But after being rescued and kept for three days on a navy ship they were put into a lifeboat and thrown a document telling them to go back to Indonesia.
"You have enough fuel to reach land in Indonesia," said the document dated December 2013. "You do not have enough fuel to continue your voyage to Australia."
The men said they were dropped very close to Indonesia and were ashore in only three hours.