In one case, gardaí say a Spanish company was deceived into transferring money to an Irish account
Three men have been arrested in connection with alleged fraud and theft.
Two men - aged 24 and 25 - were arrested in Lucan in Dublin today, and are being held at Lucan Garda Station.
According to gardaí, the arrested men are suspected of being part of an organised crime network involved international fraud and money laundering activities.
A Spanish company is said to have been deceived into transferring 'significant amounts' of money into an Irish bank account "operated under a company name by the arrested men".
A vast majority of the money is believed to have been recovered.
Meanwhile, a third man - aged 25 - was arrested in Dublin city centre, under suspicion of deceiving an Irish company into transferring a significant amount to an account he controlled.
That money has also been recovered, and the suspect is being held at Bridewell Garda Station.
In a statement, Assistant Commissioner John O’Driscoll said: "Today’s arrests by the Garda National Economic Crime Bureau of those involved in the fraudulent theft of money from businesses both here in Ireland and abroad is extremely significant.
"Today’s operations underline the importance of cooperation between An Garda Síochána, our policing colleagues internationally and financial institutions. It is particularly satisfying to recover money that was stolen and could have resulted in companies, both at home and abroad, going out of business had it not been recovered.”