The head of Operation Sovereign Borders says people smugglers are becoming even more dishonest in order to stay in business.
People smugglers are resorting to even greater duplicity to snare paying passengers.
One asylum seeker who wanted to go to New Zealand was told he'd reached Australia - after their boat ran aground in Indonesia.
People smugglers are adaptive and resilient criminals who would exploit any easing of Australian border security measures to resume their trade, Lieutenant General Angus Campbell, head of Operation Sovereign Borders, warned a Senate committee.
He said smugglers used to be able to tell clients "give me all your money and I will get you to Australia" but that is no longer the case.
"Smugglers are being forced to resort to even greater depths of dishonesty in their struggle to remain in business," he told the committee on Friday.
General Campbell told of a man apprehended in Indonesia after a smuggler promised to get him to New Zealand.
"When their boat ran aground, the client was told they had arrived in Australia. In reality they had merely come ashore elsewhere in the Indonesian archipelago," he told the inquiry.
General Campbell said it was now six months since a people smuggling venture reached Australia and no ventures had departed Indonesia since early May. There had been no known deaths at sea since December 9.
"From mid-December 2013 as an additional measure we have turned back boats where it is safe to do so," he said.
The committee is seeking information about the unrest in February at the Manus Island detention centre in Papua New Guinea.
But Australian Greens senator Sarah Hanson-Young also wanted to know about 153 asylum seekers who are aboard an Australian Customs vessel in the Indian Ocean after being intercepted en route to Australia.
She found it "extraordinary" the general had not mentioned this incident in his opening statement to the committee.
"Ultimately the buck stops with you ... these are surely issues that are at the top of your mind at the moment," she said.
General Campbell said it would be inappropriate to comment on matters now before the High Court.