The deputy Chief Medical Officer is defending a demonstration showing how antigen tests could be manipulated.
A NPHET member recently showed an Oireachtas committee how one of the tests could be tampered with using tonic water, or a buffer - which at the time was misheard as butter.
It came in for criticism, with many questioning why this was part of the presentation. The National Public Health Emergency Team is against the introduction of antigen testing for travel purposes.
Dr Ronan Glynn says the presentation was meant to be informative.