Border force officials have criticised a report which found its officers carried out illegal body searches at Australian airports and conducted inappropriate search warrants.
The Australian National Audit Office has released a harsh appraisal of the department, whom it accuses of failing to adequately address the risk of its officers using coercive powers unlawfully or inappropriately.
Immigration chief Michael Pezzullo has since conceded some "administrative deficiencies" in his ranks but came out swinging against the "loose" terms and "unworldly" analysis in the report.
Some of its "bland" recommendations were easy to swallow but its analysis was simply "not rooted in reality".
"They need to write more precisely, frankly," Mr Pezzullo told a Senate estimates hearing on Monday.
The ANAO examined 69 body searches conducted at Australian airports during 2015-16.
Five of these searches were unlawful as the border force officer was unauthorised, while 20 involved at least one uncertified officer, meaning these were inappropriate.
The audit office also examined 50 search warrants, finding almost half were used for more than one search, with one warrant used for seven separate searches, in breach of prosecution guidelines.
The department was found to have provided inadequate instructions and guidance to its officers.
"Some personal searches of passengers at international airports examined by the ANAO were unlawful or inappropriate, indicating weaknesses in the control framework," the auditor-general's office said.
"A number of searches of premises under the Migration Act exceeded the authority of the warrant which authorised them, and officers routinely questioned people without documenting their legal authority to do so."
Officers frequently failed to follow compliance, certification and record-keeping requirements, the report found.
It urged the department to improve guidance, training and supervision records about officers exercising these powers.
Immigration officials agreed with some - but not all - recommendations handed down.
It was highly likely the potentially unlawful searches and failure to comply with instructions were inadvertent and administrative breaches, not deliberate or intentional, the department said.
The term 'coercive powers' has been misused throughout the report, it added.
Mr Pezzullo was quizzed about the report less than an hour after its release, lambasting both its language and analysis.