“He is suspected of going on a spending spree with the money, particularly by buying electronic products for himself,” a senior source said.
“This individual is suspected of calling to the homes of all four victims, producing a fake personal ID and fake bank documents before leaving with their debit cards.”
The suspect was arrested at his home in Tallaght, south Dublin this morning.
He was arrested by officers from the Garda National Economic Crime Bureau (GNECB) who have been investigating the “sophisticated fraud".
He is being questioned at Clondalkin Garda Station and can be held for 24 hours.
GNECB officers are liaising with the bank to “determine whether data at the bank was compromised by his role in the institution and to establish exactly what his role was in the bank”, according to a source.
Apart from his alleged involvement in these crimes, the arrested man is also being questioned about separate money-laundering offences. This comes after detectives discovered €7,000 which had been scammed from a customer in a different bank was being stored in the suspect’s personal bank account.
“One of the crimes that he is being questioned about occurred last summer when the victim got a call which purported to be from her bank,” a source explained.
“The caller outlined in very believable terms that there was a problem with her account and that a bank employee would call to her home to collect her debit card so the issue could be resolved.
“The bank employee who is currently in custody is then suspected of arriving at her home with what appeared to be legitimate documentation from the bank, which was actually bogus, and she signed over her debit card.
“This card was then used to make four fraudulent transactions on her account.
“Investigations have established that the person who made the original phone call to the victim and the person who called to their property to take the debit card are different people.”
Sources say the crimes against the other victims followed “similar patterns”.
Detectives believe all four victims had first been identified by the gang through cyber-enabled frauds like 'smishing' and 'vishing'.
Vishing relies on convincing victims that they are doing the right thing by responding to the caller. In these cases, the victims believed they were legitimately dealing with their bank.
Officers also believe that the gang had used the smishing technique to dupe some of the victims. This is a scam where fraudsters use mobile phone text messages to trick people into opening a malicious attachment or link.
The text will instruct the recipient to click on a link to unblock or unfreeze their account. It will then ask them to log in and enter a code received by text which allows the fraudster to access the account.
Banks say they will never text a customer seeking personal information such as account numbers, passwords, pin codes, or your mother’s maiden’s name.