Australian Prime Minister Tony Abbott on Friday likened the fight against people-smugglers to war, while defending the detention centres asylum-seekers are held in as effective and humanely run.
Indonesian officials say the Australian navy has turned back at least one boat carrying asylum-seekers to its shores, although The Australian newspaper said as many as five have been secretly returned.
Abbott's conservative government has refused to reveal details of the incidents or other "operational matters", sparking claims from the Labor opposition that it is overseeing a "Stalinist"-style media blackout.
"In the end, we are in a fierce contest with these people-smugglers," he told a breakfast television programme.
"And if we were at war, we wouldn't be giving out information that is of use to the enemy just because we might have an idle curiosity about it ourselves."
Abbott said he would not release information which would be exploited by people-smugglers to the peril of their customers "and to the tremendous disadvantage of our country".
The conservative Liberal Party leader, who won power in September polls after campaigning to "stop the boats", has introduced the military-led Operation Sovereign Borders to crack down on asylum-seekers coming by boat.
Under the policy, Australia will turn back boats to Indonesia when it is safe to do so, while those who reach Australian territory will be processed within 48 hours and quickly sent to Pacific island camps on Nauru or Papua New Guinea.
Australia's tough policies have irked Jakarta, which has warned that turning boats back could breach Indonesian territorial sovereignty.
Rights groups have also criticised the camps as harsh and the process under which the asylum-seekers are dealt with, but Abbott defended them.
"We don't apologise for the fact that they're not five-star or even three-star hotels, nevertheless we are confident that we are well and truly discharging our humanitarian obligations," he said.
"People are housed, they're clothed, they're fed, they're given medical attention. They're kept as safe as we can make it for them. But we want them to go back to the country from which they came."
Abbott said the vast majority of asylum-seekers arriving by boat were economic migrants.
"Let's remember that every single one of the recent arrivals has come to Australia through a series of other countries where they could easily have claimed asylum but they choose not to do that because they are seeking a migration outcome here in Australia," he said.
The number of asylum-seekers coming to Australia by boat has dropped dramatically under the new government, which has maintained the previous Labor administration's policy of sending all arrivals to Nauru and PNG.