Gardaí have warned homeowners to beware of telephone scammers posing as "security managers" based in high-end retail stores.
More than 30 people have lost thousands of euro after being asked to provide bank account details to a mystery caller, who uses a sophisticated scam to steal money known as 'vishing' because it's a voice-call form of an email fraud called 'phishing'.
In one case, a victim lost €38,000. Two others lost €17,000 and €14,000. Gardaí warned that people with landlines, in particular the elderly, were being targeted.
The scammers phone landlines and identify themselves as security managers in a well-known store.
They inform the householder that suspicious activity has been recorded on their credit or debit card, suggesting it is being used. They ask the cardholder to contact their bank or garda station with security details.
However, when the householder hangs up and goes to call their bank, the scammer remains on the line and then impersonates the garda or bank official.
This is possible because of "clear down time", where if the person making the call doesn't hang up, the line remains active for up to 60 seconds.
The customer hangs up the phone and assumes they are ringing either their bank of local garda station, but in fact the person they speak with is an accomplice or the scammer themselves.
Thieves have used multiple aliases to garner the trust of targets, before asking them to transfer funds from their bank account to a third-party account "for safety". These accounts are in the UK and Indonesia.
Detective Inspector John Foudy from the Garda Bureau of Fraud Investigations said they had been aware of the telephone scam for a number of weeks, but had not been able to track down any suspects.
They are unable to access the stolen money as it rests in an overseas account.
Detectives believe thieves are using the phone directory to target victims, as all have landlines and there appears to be an alphabetical pattern.
Householders are urged to ensure they hear a dial tone before calling gardaí or their bank, and to report any suspicious activity.