Irish health chiefs have started an investigation to discover how the nurse was allowed to continue working in Donegal while unregistered.
It has emerged that the female nurse took forensic evidence from victims at the Sexual Assault Treatment Unit in Letterkenny after failing to renew her registration.
Irish law requires that all nurses must be registered with the country’s nursing board before they can work but the nurse in question had allowed her €88 a year registration to lapse in 2009.
The Health Service Executive was informed that she was no longer registered but she continued to work illegally.
All sexual assault cases featuring forensic evidence gathered by the nurse could now collapse if the evidence is challenged in court.
And a spokesperson for the nursing board has told the Irish Independent that it has no power to prevent her coming back permanently to the register once she pays her fee.
However the paper also reports that a nurse who continues to work while not on the register is doing so illegally and could be prosecuted under Section 49 of the Nurses Act, carrying a possible fine of more than €1,000 or 12 months jail, or both, if convicted.
Around 800 nurses a year fail to renew their registrations in Ireland. Employers are automatically notified when a membership lapses.
All 25 victims have been informed of the blunder and offered counseling.