A "very small number" of workers at Moy Park's Ballymena site have tested positive for Covid-19, the company has confirmed.
There are around 1,400 employees at the facility.
The food firm said it was working with the Public Health Agency (PHA) and those affected were self-isolating on full pay.
Health Minister Robin Swann told BBC radio this morning it had been "designated" by PHA as an outbreak.
He said it was important to avoid speculation.
He added: "We have always said we will expect outbreaks and clusters as we start to ease restrictions, but what we really need is for people to interact with test track and tracing so we can manage them."
In a statement today, Moy Park said: "We have been informed that a very small number of our employees in the Ballymena site have tested positive for Coronavirus.
"The individuals affected have been self-isolating on full pay in line with our COVID sick pay scheme and we are in contact with them to ensure they have the support they require.
"We continue to work closely with the Public Health Agency and other government agencies, following their advice and protocols.
"As Coronavirus has spread across the communities in which we live, we are doing all that we can to help keep the virus out of our facilities and help prevent its spread.
"Staff safety is our number one priority and we continue to strictly follow all safeguarding procedures across our sites, such as enhanced cleaning and hygiene regimes, thermal temperature scanning, Perspex screens, additional PPE and social distancing measures.”
