Independent TD Denis Naughten has called for the retesting of workers at the Kepak meat factories and other plants around the country where there has been a high percentage of staff diagnosed with the coronavirus.
Mr Naughten said he had serious concerns about the procedures that followed the initial testing of workers at plants two weeks ago.
Deputy Naughten said he would support the case now for retesting those workers who were negative in the first tests 14 days ago.
Speaking under Dáil privilege on Thursday, he said: "Because of this failure to self-isolate staff members who potentially showed no sign of infection, they could have been spreading the infection asymptomatically," he said, "this has resulted in a situation where the negative results issued to employees are worthless, as they could have become infected in the interim period by employees who were asymptomatically positive while awaiting test results."
Mr Naughten said he understood the fears of workers and locals about what had happened in the meat factories.
"All workers who were tested are supposed to be out of the plant for 14 days if they are positive," Deputy Naughten said, "the role played by public health in the screening of the virus, testing process and the contract tracing process is the real area of concern here."
The Kepak group has declined to comment on Deputy Naughten's comments.
In a separate development this evening, it has been confirmed that senior gardaí visited the Kepak plants in Ballymahon, Co Longford and Athleague, Co Roscommon in the last ten days to advise management and staff of the necessity to follow guidelines on social distancing in the plant and in their homes - after tests and while they are waiting in quarantine.
Gardaí were responding to concerns expressed by the general public and political representatives in both areas who had told them that social distancing regulations were not being followed by workers in many cases.