The Privacy Commission and the Department of Immigration are investigating how the personal details of about 10,000 asylum-seekers were revealed on the Department's website.
Minister for Immigration, Scott Morrison described the incident as "unacceptable" and "a serious breach of privacy".
"I am advised that an immigration detention statistics report released on the Department of Immigration and Border Protection's website on 11 February 2014 inadvertently provided access to the underlying data source used to collate the report content, which included private information on detainees," the Minister said.
"This is an unacceptable incident. I have asked the department Secretary to keep me informed of the actions that have been initiated, including any disciplinary measures that may be taken, as appropriate," he said.
The Minister said KPMG has been hired to review the breach and an interim report is expected by next week.
The Department has asked KPMG to review all data publications and to ensure that mechanisms will be in place to make sure it doesn't happen again, Mr Morrison said.
He said when the Department became aware of the breach immediate steps were taken to remove the documents from the website.
"The information was never intended to be in the public domain, nor was it in an easily accessible format within the public domain," he said.
"I am advised the department has ensured all possible channels to access this information are closed, including Google and other search engines.''
Describing the breach as a "serious incident", Privacy Commissioner Timothy Pilgrim also said he would investigate how it had occurred.
Guardian Australia reported on Wednesday that the full names, nationalities, location, arrival date and boat arrival information of about one-third of asylum-seekers in Australia were available on the Department's website.
It said the details covered all asylum-seekers, including children, held in mainland detention facilities, on Christmas Island and several thousand held in community detention.
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