There was a 35% increase in the number of complaints of driving-licence fraud last year.
According to details released under the Freedom of Information Act, the Road Safety Authority (RSA) says there were 247 reports of people illegally obtaining licences in 2017.
But this rose to 383 in 2018 - and there have been a further 213 reports this year.
The RSA has previously said public services cards would help to crack down on this type of fraud.
Aisling Reid, from the Parc road-safety group, says it is vital illegal drivers are kept off the roads.
"It's quite alarming that there has been an increase in the number of fraudulent licences," said Ms Reid.
"It's a fairly stringent system when you are applying for a licence so they really need to get a hold of how people are able to obtain them fraudulently."
The RSA refers cases of suspected fraud to the Gardaí for investigation.
Ms Reid said that illegal drivers cause insurance prices to increase.
"They're not insured if you're caught driving on a fraudulent licence and you cause a crash your insurance is null and void," said Ms Reid.
"If people who are driving on fraudulent licences are involved in any crash, it is going to hike the price of insurance up because they are uninsured."
The CEO of the RSA says she would be more concerned if they were not investigating complaints of driver licence fraud.
"It's very important to point out that our systems are very robust," said Moyagh Murdock.
"We have a fraud section that looks at this, that is their sole role.
"We have very tight due diligence on all licence applications so it may just be a bunch of people who think they may get a licence.
"I would be more concerned if we weren't picking it up and they were being issued."
Decrease of 9.7% in new private cars licensed in July 2019https://t.co/P5MwYUbsqF #CSOIreland #Ireland #IrishTransport #TransportIreland #Transport #VehicleLicensing #NewVehicle #Business #BusinessStatistics pic.twitter.com/IfjIll9O9x— Central Statistics Office Ireland (@CSOIreland) August 9, 2019
Meanwhile, the number of new private cars licenced for the first time in July 2019 was down 9.7% on last year.
According to the latest CSO data, 18,741 new private cars were licenced last month.
In the first seven months of this year, a total of 96,380 new private cars were licenced marking a 7% decrease on the same period in 2018.
Electric and hybrid vehicles account for 10% of the 96,380 new private cars licenced this year.