A probe is under way into an alleged attempt to fraudulently use credit card details given to the local property tax helpline.
A call centre worker was suspended and a Garda investigation launched after someone tried to use the credit card numbers of some callers.
No arrests have been made.
The Revenue Commissioners, which is collecting the tax, said it was extremely concerned about an incidence of attempted fraud by an employee of Abtran, the Cork-based call centre which operates the outsourced helpline.
A spokeswoman said the allegation was being treated very seriously.
“Revenue understands that details in relation to 11 credit cards were improperly obtained by an unauthorised employee but most importantly no cardholder has suffered any loss,” she said.
Socialist Party TD Joe Higgins has demanded that Revenue chairwoman Josephine Feehily go before the Oireachtas finance committee to answer questions.
Nearly 640,000 homeowners have signed up for the controversial local property tax so far, with nearly 300,000 calls made to its helpline.
Abtran also provides a telephone-based online filing credit card service, which it maintained is in a secure ring fenced environment.
Management confirmed it suspended an employee who was working on the team supporting the local property tax information service over the alleged unauthorised use of credit card numbers obtained.
It said that late on Thursday it emerged that someone answering inbound calls had unnecessarily asked customers for banking information.
“Following an investigation, where the company listened back to all calls conducted by the individual, it is apparent that the individual obtained the credit card details of 11 customers,” it said.
“The individual was suspended immediately from service pending further disciplinary action towards dismissal.
“Abtran also reported the matter immediately to the gardai who met and interviewed the person in question on Friday morning,.
“It is understood that the individual did attempt to effect transactions but failed to do so.
“That is also the subject of the Garda investigation.”
Credit card companies and the Data Protection Office have been notified and affected customers are being contacted.
Anybody with concerns can call a dedicated Revenue number, 1890-22-63-36, from 9am.
Revenue and Abtran maintains this was an isolated incident and that all payments made online are secure as no one in Abtran has access to any of Revenue’s IT systems.
Abtran stressed the incident did not involve access to electronic payment systems, which are fully secure and which automatically block unauthorised access.
“Instead, the individual had used a pen and paper to take a note of credit card details that the individual requested from customers,” call centre management said.
“The individual was not a member of a payments authorised department within Abtran.
“The individual had no authority to request any such details of customers and should not have done so.
“Those actions, and the customers potentially impacted, have been identified.”