Dr Ciara Kelly has said the Department of Health's advice that restaurant toilets are riskier than hotel toilets sounds as if it's completely made up.
The GP-turned-broadcaster said she doesn't understand the logic that hotel toilets are safer than restaurant toilets in stopping the spread of Covid-19.
The Department of Health claims hotel guests are less likely to use the communal toilets than people in restaurants.
It believes that hotel guests are more likely to return to their rooms to use the toilet rather than using the nearest one while more customers are mixing and using fewer facilities in restaurants.
It also blamed indoor dining in restaurants over Christmas as a "major contributor" to the third wave in early 2021.
The Department of Health's claims are contained in a legal defence on the restrictions on indoor dining in a High Court case taken by the Restaurants' Association of Ireland.
Dr Ciara said the advice is insulting to restaurant owners.
Speaking on Newstalk, the presenter said: "If you were a restaurateur, hearing that your toilet is riskier than someone else's toilet is kind of insulting.
"It doesn't really make a lot of sense. It is daft.
"This sounds more like an excuse than a reason. If I were a restaurateur, I would feel insulted because it sounds to me like they are clutching at straws and kind of nearly making things up.
"Making things up to justify their reasons and if you don't have a justification for a good reason, then maybe it's not a reason at all.
"It makes absolutely no sense whatsoever."
The Government’s defence is set out in an affidavit from the deputy chief medical officer Dr Colette Bonner.
She said the number of hotel guests is limited whereas a restaurant can have multiple sittings.
Dr Bonner said: “Each hotel guest would have their own toilet facilities, and there would generally be a number of other toilet facilities throughout hotels.
"The more limited facilities generally available in non-hotel restaurants present a greater risk by virtue of the greater likelihood of increased mixing between patrons.
“In the circumstances, the decision to differentiate between hotel restaurants and non-hotel restaurants is reasonable at this stage of the gradual reopening of society and the economy.”
