Fraud squad detectives have arrested a 24-year-old man who set up a "false overdraft" of €50,000 when he was working in the head office of one of Ireland's biggest banks.
The suspect, who is from north Co Dublin, is described as a "computer whizz kid" and has been the subject of a major probe by the Garda National Economic Crime Bureau (GNECB) for three years.
The Herald can reveal he was re-arrested on Thursday by officers from Blanchardstown Garda Station who had previously questioned him about the elaborate scam which was carried out at the bank's city HQ.
Senior sources say that while working in the head office, the Dublin man was "able to manipulate a flaw" in his employer's online system.
"Essentially the suspect created a false overdraft facility for himself by means of his excellent computer skills," a senior source said last night.
"He is suspected of stealing just under €25,000 before gardai were alerted to his activities.
"In particular, the GNECB have been focusing on three incidents of alleged theft which happened in 2017 in relation to the false overdraft when he was working for the bank.
"These are the withdrawal of €10,000 on two occasions, as well as the alleged theft of €4,500 on another occasion," the source added.
The suspect was not previously known to gardai for involvement in crime and he is expected to be charged before the courts in the coming weeks.
Sources say that this case is just one of a number that the GNECB is investigating in relation to "people working in banks who have access to computer systems and are involved in fraudulent activity".
"In essence, in some cases they are using their positions of trust to access customers' accounts and manipulate weaknesses in the banks' IT systems for their own criminal ends," a senior source explained.
A woman based in a bank in the Tallaght area is also being investigated for similar offences.
In a separate case, a northside-based suspect in his 20s was arrested earlier this year after gardai became aware that he was "accessing customers' accounts and attempted to transfer money from these accounts".
It has been a busy week for fraud squad detectives who are also playing a key role in a separate international investigation into a sophisticated €15m Covid-19 scam.
They have been carrying out further enquiries into a man in his 40s based in Castlerea, Co Roscommon, who they suspect played a central role in that fraud, even though he bizarrely claims he is a victim of the same scam.
The man, who is originally from Co Clare, was questioned by specialist officers for a number of hours on Friday of last week before being released without charge.
It is understood detectives have established that he travelled to the Netherlands as part of his alleged role in the huge scam.
The probe was launched when German health authorities made an upfront payment online of €1.5m for face masks, only to discover the website advertising the personal protective equipment (PPE) was being operated by scammers.
The €1.5m has now been frozen in the Roscommon-based suspect's bank account.
Meanwhile, the coronavirus pandemic has led the GNECB to issue a number of warnings about separate online scams.