Dr Tony Holohan has urged people not to buy the antigen tests being sold in Lidl from today saying he is "very concerned".
The retail giant is selling packs of five test kits for €24.99, and these are available in all 168 stores.
But speaking at a press briefing today, the Chief Medical Officer said he does not encourage people using them, fearing they will "falsely reassure people".
Dr Holohan said: "I'm very concerned about these tests. Supermarkets are free to sell what they sell, but it's what could happen.
"People are generally confused about antigen tests, and we think it has a role to play in our response but in strictly controlled circumstances where we know it's going to work and what the result could mean. Individuals could get inappropriate reassurance that they're safe when they're not.
"Someone could go into the supermarket and buy a pound of sausages and charcoal for a BBQ, as well as a test. That represents a real risk.
"These tests, if not used properly, have little role to play and if it falsely reassures people, that's a real risk.
"If you had a wedding that was taking place indoors - if one person attends that with the disease but with an antigen test of 50% performance, in half of the circumstances, the test won't pick up the case.
"There's a real risk of a superspreader then.
"Don't buy these and use them."
DR Ray Walley added: "Patients in some GPs were using them regularly. The antigen test was negative and then they took a PCR test was positive.
"That's happened to a number of GPS. That person had a vulnerable relative and they had used antigen tests to go to work."
