Up to 60 staff at a meat plant in Edenderry, Co Offaly, have tested positive for coronavirus.
Rosderra Meats says it has put in place significant Covid-19 control measures.
All staff have been told not to come to work when they are feeling sick or have symptoms of the virus.
Rosderra Meats also has over 120 cases of Covid-19 at another factory in Roscrea, Co Tipperary.
Former Minister for Communications, Independent TD Denis Naughten has expressed fears that a second wave of Covid-19 could hit the country when restrictions are eased next week.
Mr Naughten said he feared the second wave because of the increase of clusters of Covid-19 in meat plants which could be replicated in other industries when restrictions are eased from May 18.
The rate of infection in some meat plants was one third and half of the work force he told Newstalk Breakfast.
The controls in meat plants are not working, he said.
Mr Naughten questioned the number of veterinary staff in the Department of Agriculture responsible for the enforcing of regulations in meat plants.
The problems in meat plants are as a result of a combination of factors, he said, such as the lack of information for both employers and employees on how the regulations should be implemented.
The first infections in meat plants happened six weeks before screening of staff commenced, this time lag was a concern, he added.
It seemed like lessons were not learned after what happened in nursing homes.
The Roscommon TD said he did not think the problem with clusters of workers in meat plants having Covid-19 would have an impact on meat supply, though it could have an impact on “the kill.”
His fear was about the management of the system “not just in the meat industry, but how it (virus) is being managed by the HSE.
There is a significant problem with contact tracing and if that is replicated next week, that will be a big problem.
SIPTU’s deputy general secretary for the private sector, Gerry McCormack told RTÉ radio’s Morning Ireland that the problem was that from the beginning of the pandemic some employers in the meat industry did not take the issue seriously.
“When this crisis began plants were given guidelines, not protocols. There is a question if some should have opened, some were not essential.
Some employers didn’t take it seriously and failed to implement social distancing and didn’t put processes in place to help workers, he said.
Mr McCormack compared the meat and dairy sectors, saying that the dairy sector was very well regulated with a completely different demographic.
He pointed out that between 70% and 90% of workers in the meat industry are migrants, many cohabitating in accommodation.
They were also afraid to say anything if they became ill.