The Irish woman was one of three patients identified by cops who had handed over tens of thousands to the scammers in a Business Email Compromise (BEC) fraud.
The Guardia Civil arrested four men and two women in connection with the scam, including a Romanian man who they believe is the ringleader of the group.
The investigation into the gang began last August when the manager of the clinic contacted cops to say three of his patients had been victims of the same scam.
Police then discovered that the scammers had used malware sent by email to access the clinic’s computer system, Spanish newspaper La Vanguardiareported.
Once they accessed the system, they obtained the data of patients and emailed them posing as the clinic.
The patients believed they were sending money owed to the clinic but were in fact sending it to accounts of mules working for the gang.
The Guardia Civil has identified at least three victims including the Irish woman as well as German and Dutch women.
Before the victims realised what had happened the gang then sent the money to other accounts in the Netherlands and used a Dutch company to try to hide the origin of the cash.
Police in Amsterdam also collaborated on the investigation, which was led by the Guardia Civil.
They first identified three money mules used by the gang. Two of the men were originally from Mali and based in Almeria, while a woman who is from the Ivory Coast but living in Malaga was also arrested.
They also identified a 41-year-old Romanian man living in Rosquetas de Mar in Almeria in June as being behind the scam.
The man, who police said has good computer skills, was arrested on June 8.
A fourth money mule, a 41-year-old man from Nigeria, was also arrested that day as part of the operation.
They appeared in court charged with offences including membership of a criminal organisation, discovery and disclosure of secrets, continued fraud, money laundering and identity theft.
They have all been released from custody with a number of restrictions as they await trial.
Reports in Spain say some of those arrested have records for similar offences.
Email scams have grown in popularity across the world in recent years.
Gardai said at the end of last year they were identifying around 400 money mules in Ireland alone every month.