Doctors believe that if the test is not taken from swab sites sufficiently deep in the nasal cavity the number of false negative tests could be even higher.
This follows a number of doctors at several Irish hospitals raising concerns regarding the tests when such swab tests either failed to confirm Covid-19 in patients displaying symptoms or registered different results from blood tests.
Infectious Disease Specialist with the Royal College of Surgeons in Ireland says he is not surprised that the tests a coming back with false negative results.
"In the early stages of infection, if you are infected today, in the next two days, you are negative. It takes a while for it to become positive and also, it only lasts for about five or six days, so even as people are still coughing and still perhaps getting very sick in the later stages, it can also be negative later on.
"I would still say it's a very valuable test because if it's negative, it really points to you not being infectious," he added.
