A joint review by Defence and Customs has found Australian ships mistakenly entered Indonesian waters six times, with Immigration Minister Scott Morrison labelling the incursions “highly regrettable”.

The breaches, which have prompted Mr Morrison to promise Indonesia such mistakes will not happen again, occurred between December last year and January 2014 and were contrary to Australian government policy and operational instructions for Operation Sovereign Borders.

“On each occasion the incursion was inadvertent, in that each arose from incorrect calculation of the boundaries of Indonesian waters rather than as a deliberate action or navigational error,” the review says.

It examined all patrols conducted by Navy and Customs vessels on Operation Sovereign Borders between December 1 and January 20.

Australia has apologised to Indonesia for the unintentional incursions.

The review said the instructions to commanders were quite clear and vessels were supposed to stay 12 nautical miles outside the Indonesian archipelago baseline.  

There was also a clear requirement for maritime activities to be conducted safely and that dominated mission planning.

“Despite clear guidance to operational headquarters and assigned units, the imperative to remain outside Indonesian waters did not receive adequate attention during mission execution or oversight,” it said.

Customs released only the executive summary of the review which did not disclose what the Australian vessels were doing when they entered Indonesian waters and just how far they intruded.

The chief of navy will consider cases where navy ships breached Indonesian waters to assess if there was any lapses in professional conduct.

Training for Australian crews involved in Operation Sovereign Borders will be amended to emphasise staying outside Indonesian waters.

Morrison responds

Mr Morrison has backed the report’s findings, saying they show the incursions, although “highly regrettable”, were “accidental”.

The report says the Navy is only supposed to carry out operations to deny asylum seekers passage to Australia outside 12 nautical miles of Indonesia’s archipelagic baseline, and where it is safe to do so.

The incursions were first detected on January 15 when it was realised operations reports did not correlate with where the vessels were supposed to be patrolling.

The report made 10 findings and five recommendations urging the Chief of Navy and the head of Customs to review breaches “with regard to any individual lapses in professional conduct”.

It also encouraged a review of procedures and further training.

It was baseless for them to say that what happened was unintentional or a form of ignorance.

Mr Morrison says the chief of the Navy, vice admiral Ray Griggs, briefed his Indonesian counterpart about the findings of the report.

“Subsequent discussions have been had through our mission and formal notes have been provided also to the government of Indonesia through the diplomatic channels and there is the standing offer of further verbal briefings if requested,” he said.

Mr Morrison says the Government has already apologised to Indonesia.

But a spokesperson from the Indonesian Navy told the ABC last week that the apology is not the Federal Government’s official stance because it was done through a media release.

Indonesia is also unlikely to accept Australia’s claim that the breaches were an accident and not deliberate.

“In this day and age, navigation equipments to determine [the] position of war vessels are very modern,” Untung Surorapti, a spokesman for the Indonesian Navy, told the ABC last week.

“It was baseless for them to say that what happened was unintentional or a form of ignorance.”

When asked if he thinks Indonesia’s concerns have been allayed, Mr Morrison said: “I do have that confidence based on the exchanges that have been reported to me.”

“I’m satisfied that we’ve gone through a very good process with the government of Indonesia. We have been very forthright,” he said.

“The minute we knew about it, we advised them, we apologised, we initiated review, we have advised them of the outcomes of that review in some detail.”

Mr Morrison says any decision on disciplinary action over the incursions is a matter for the Chief of the Navy.