A teenager was arrested as the fourth suspect in cases where scammers posed as doctors to extort money from people, police said on Friday.
The new arrest concerns a 19-year-old woman.
The scammers, police said, called people telling them their relative needed immediate medical care and that they must hand over large sums of money.
For the case, two men, aged 52 and 25, as well as a 47-year-old woman were arrested last week.
The three were allegedly involved in three separate cases between April 16 and May 4 this year, during which they extracted €18,500.