A cockroach infestation caused the closure of three restaurants in the Powerscourt Centre in Dublin.
La Corte, an Italian restaurant, Café Fresh, a vegetarian restaurant, and Quiznos, which sells sandwiches, were served with closure orders in November following inspections by the HSE's environmental health officers.
A closure order is served when it is deemed that there is or there is likely to be a grave and immediate danger to public health on the premises.
The chief executive of the Food Safety Authority of Ireland (FSAI), Dr John O'Brien, said the infestation was so bad that officers were forced to shut all three premises at once.
"The common denominator was a cockroach infestation which affected all three premises. It's very unusual for the authority to close three premises in the same area.
"The officer concerned had no option, because there was a grave danger to public health, but to close those premises."
The three restaurants have since been reopened after pest control officers were called in to deal with the problem.
Another restaurant in the centre, Ba Mizu, had its kitchen, locker room and dry store shut in October by the FSAI, but for a different reason. It too has reopened.
Nobody from the Powerscourt Town Centre was available for comment.
The Italian restaurant Buona Sera in Upper Kilmacud Road, Dundrum, the Canton Garden Restaurant in Summerhill, Co Meath and Shan in Temple Bar, Dublin, were also served with closure orders.
Dr O'Brien urged food businesses to be particularly vigilant about food safety in the lead-up to and during the Christmas party season.
"Food businesses must ensure that they have robust food safety systems in place to cope with this extra demand," he said. Short cuts would not be tolerated.
