6,000 women will be asked to have a repeat smear test due to a confusion between CervicalCheck and laboratories.
Many of the samples were rendered invalid because they had not been tested by laboratories within a 30 day time period.
Peter McKenna, acting clinical director of the HSE's cervical screening programme, has said that the patients who need repeat smears will be contacted by the end of the next week.
Speaking on Morning Ireland today, he said that one part of the test had not been carried out inside of the accepted time frame agreed by the manufacturer.
"What appears to have happened is that the test should be carried out within 30 days of the smear being taken," he said.
"What appears to have happened is that the laboratories started counting the 30 days from the time the smear came into the laboratory, rather than from the time that the smear was taken in the clinic."
McKenna said the HSE was informed of the problem in November of last year. An investigation will be launched into why the mix up occurred.
He said that the confusion is
a separate issue to the enormous backlog of smear tests following the introduction of a free smear last year.
This decision was made after the CervicalCheck scandal which saw over 220 women given false negative results.
Many of the women went on to develop cervical cancer in the years following their tests with some others, including
Orla Church, passing away.
The women asked to return to their GPs for a repeated smear should be notified by the end of next week.
Their tests should be processed as a priority.
