Gardaí are investigating alleged breaches of public health regulations at a property in Cork earlier this month.
Meanwhile, a secondary school in Cork has appealed to parents not to allow their children to attend parties or social gatherings.
Pobalscoil na Tríonóide in Youghal said it had been notified of 14 confirmed cases of Covid-19 by the Department of Public Health in HSE South.
After consulting with public health officials, Pobalscoil na Tríonóide's board of management decided on Sunday to close the school.
"This decision has not been taken lightly but is necessary in order to complete contact tracing and ensure that all close contacts have been identified and advised by Public Health," principal Séamus Ó Ceallacháin said in a statement.
Students were taught remotely on Monday, but have since returned to the classroom.
The school said students must continue to comply with public health guidelines to ensure that in-school teaching and Leaving Certificate examinations continue as planned.
"We therefore ask that you do not allow your child to attend parties or social gatherings until public health guidance advises that it is safe to do so," it said.
"However, the actions of a few could jeopardise these efforts, and in so doing, compromise the running of the Leaving Certificate examinations," it added.
However, the school said that in the event of wet weather students will be required to remain outdoors during lunch breaks.
The HSE said it did not comment on individual cases.