The department has confirmed inquiries are underway into claims that Irish citizens are using passports issued in their Gaelic names to double-dip on working visas in Australia, The Irish Independent reports.

But Immigration has not said how widespread the scam is or for how long it has been used.

The department believes that Irish emigrants have been obtaining passports in their native-language forms of their name, in many cases completely unrecognisable to non-Gaelic speakers from its anglicised spelling and pronunciation.

The new passport then allows the worker to obtain a working visa after their previous one has expired and they are no longer eligible to live and work here, with Australian authorities thinking they are dealing with a new applicant.

Irish citizens are entitled to a second passport featuring the Gaelic version of their name if it appears on their birth certificate or they can convince their nation's Foreign Affairs department they have been using their Irish language identity in their everyday lives for at least two years.

Department of Immigration and Border Protection, which sent public servants to Dublin in February to discuss the problem with their Irish counterparts, told the Independent it was investigating.

"The Department is aware of and is investigating a migration fraud involving Irish applicants using new passport features to access Australian visas," a spokesperson told the Dublin newspaper.

"Accurately identifying non-citizens underpins the integrity of Australia's migration, visa and citizenship programmes and is the basis for all security and character checks completed before making a decision about whether to grant a visa to come to Australia."

The Irish Department of Foreign Affairs confirmed that it was taking steps to ensure the right to an Irish language passport was not abused by its citizens in identity fraud.