Border Force boosted during election time

Extra Border Force and navy personnel were deployed to waters in Australia's north-west during the election campaign, Home Affairs Minister Peter Dutton has confirmed.

"The bureaucracy took that decision during the caretaker phase, that they would deploy more assets within the region," he told reporters in Brisbane on Thursday.

"Both in terms of aerial surveillance as well as on-water assets, and that's the decision that they took."

Mr Dutton's comments come after it was revealed a boat with 20 asylum seekers from Sri Lanka tried to reach Christmas Island last week.

The boat was intercepted before the asylum seekers were returned to Colombo.

The minister says the boat left in early May and people smugglers were trying to test the re-elected government's resolve.

"There seems to be some chatter around that the Sri Lankans might have changed their position, or that Australia's changed its position and that we won't send people back to Sri Lanka," he said.

"That is not the case."