Almost 3,200 cases of suspected passport fraud have been investigated by the Passport Service over the last three years.
From that total, 184 separate cases were passed on to An Garda Síochána for investigation, the Passport Service has said.
Overall, 229 passports were cancelled as a result of suspected fraud, according to figures released under FOI.
However, suspicious activity related to passports showed a sharp drop last year with the number of cases investigated dropping from 1,644 in 2019 to 1,033 in 2020.
Referrals to the gardaí also dropped significantly from 67 to just 20.
The Passport Service said this partly resulted from increased staffing in their integrity unit and stronger systems for stopping bogus applications before they were even submitted.
Lower numbers of passport applications were also recorded in 2020 due to the Covid-19 pandemic with massively reduced levels of international travel.
The number of passports cancelled also declined with just 22 cases last year, compared to 77 in 2019 and 130 in 2018.
The Passport Service said they had invested considerable resources in their integrity section since 2017 to tackle the growing problem of fraud.
They said: “The Passport Service has endeavoured to improve all aspects of detection to protect the integrity of the Irish passport.”
Staffing in their investigative unit has been bulked up with new and improved systems put in place for finding fraudulent applications.
They said: “These resources along with new procedures introduced to the Passport Service have prevented fraudulent applications from being submitted, closing down avenues of access previously used by the fraudulent applicant.”
An information note said all suspected attempts of fraud detected were evaluated with some resolved at an early stage and others passed to an investigator.
They said: “Investigations are resolved in different time frames subject to the level of investigation required.”
Not all cases of fraud have to be reported to gardaí with some not reaching the threshold for police investigation.
“While each year there are a large amount of investigations and inquiries opened and carried out by the Integrity Section, only those where breaches of the Passports Act 2008 are established rather than suspected are reported to An Garda Síochána,” they said.
The Passport Service said they could not comment on the most common types of fraud for “operational and security reasons” and to protect the integrity of the passport system.