Federal Police have raided the Department of Home Affairs over leaks in relation to the au pair affair that embroiled Cabinet Minister Peter Dutton last month.

Key points: Police have executed a warrant inside a Home Affairs office in Canberra

Police have executed a warrant inside a Home Affairs office in Canberra Leaked documents detailed the Minister's intervention in the visa cases of two au pairs

Leaked documents detailed the Minister's intervention in the visa cases of two au pairs The AFP says it has conducted "a number of activities" in its investigation

AFP officers entered one of the department's buildings in Canberra on Thursday morning, with suggestions they were seeking to secure evidence on computer systems.

Police received a complaint from the department last month about an "unauthorised disclosure of information".

The ABC understands a warrant was executed inside the building.

A trove of emails between Mr Dutton's office, Home Affairs personnel and others was leaked to Labor last month, revealing there had been ministerial intervention to prevent the deportation of a French woman in 2015.

Alexandra Deuwel, 27, was planning to work as a nanny for Adelaide pastoralists Callum and Skye MacLachlan at their Barossa Valley farm in breach of her tourist visa.

Mr MacLachlan is a cousin of AFL boss Gillon McLachlan.

Peter Dutton intervened when Alexandra Deuwel was detained by immigration officers. ( Supplied: Facebook )

Mr Dutton, the Minister for Home Affairs, was also accused of helping former Queensland Police colleague Russell Keag to secure the release of an Italian woman who had also come to work as an au pair.

The Minister has emphatically denied acting inappropriately in both instances and even accused former Australian Border Force commissioner Roman Quaedvlieg of fabricating evidence to a Senate committee investigating the au pair affair.

Mr Quaedvlieg's submission to the inquiry recalled a phone call he received from Mr Dutton's chief of staff, Craig Maclachlan, in June 2015.

"He (Mr Maclachlan) told me that the Minister's friend, whom he referred to as 'the boss's mate in Brisbane', had encountered a problem with his prospective au pair who had been detained at Brisbane Airport by immigration officials due to an anomaly with her visa," Mr Quaedvlieg wrote in his submission.

Mr Dutton said Mr Quaedvlieg's recollection was impossible because Mr Maclachlan did not join his office until October 2015.

The AFP on Thursday confirmed it had received a referral from the Department of Home Affairs on August 30 "regarding an unauthorised disclosure of information".

"The matter has been accepted for investigation," police said in a statement.

"The AFP has undertaken enquiries and conducted a number of activities in relation to this investigation."

An Australian Federal Police car leaves the Home Affairs office in Canberra. ( ABC News: Matthew Doran )

Mr Dutton previously accused his former Border Force boss of providing information to Labor, telling Parliament a former colleague of Mr Quaedvlieg now worked in Opposition Leader Bill Shorten's office.

On Thursday, Mr Quaedvlieg said he was "hopeful and optimistic that the AFP will find the evidence" to prove he was not the source of the leaks.

"Unauthorised disclosures of confidential information can be criminal offences and as such ought to be investigated expeditiously by the AFP," he said.

Mr Quaedvlieg added he was disappointed at the slow progress of investigations into "the disclosure of confidential information from the investigation into allegations against me".

The former senior public servant was sacked by the Governor-General in March amid an investigation by the Australian Commission for Law Enforcement Integrity into his role in helping his girlfriend secure a job with his agency.

The raids mark an escalation of a police investigation, instigated by the Secretary of the Home Affairs Department, into what was described as a "potential breach of the criminal law."

In confirming he had referred the apparent leak of sensitive Border Force operational documents to the AFP, Michael Pezzullo last month told a Senate inquiry it was "my responsibility as Secretary to ensure that such matters are drawn to their attention."

Mr Pezzullo explained that leaks of protected information from the public service "stab at the heart of public administration" because "you basically couldn't do your job if you couldn't communicate and record your transactions" as a government official.

Hinting that the Secretary had a fair idea what was in the haul of documents that had escaped the Department's rigorous security procedures, Mr Pezzullo told the Senate "all our systems are networked. Document transmission is traced, down to the level of printing, down to the level of transmission to external accounts."

The Secretary expected Federal Police to "establish... both the exfiltration of the information from our network, to whom it was exfiltrated and what, potentially, happened to it thereafter."