The Food Standards Agency is leading an investigation into a meat and poultry coldstore operated by Euro Freeze in Lisnaskea, in County Fermanagh.
The contents of the cold store have been detained
The agency's focus is on repackaging and re-labelling activity.
In a statement the agency said there was emerging evidence suggesting the use of illicit health marks.
The investigation follows a visit to the premises last week by Department of Agriculture officials and police. The coldstore's licence has been suspended.
The contents of the coldstore were detained after the initial visit and the distribution of its meat has been stopped.
The FSA said at this stage no food safety issues have been identified.
It added that it would carefully examine the evidence as the investigation continues and would try to trace any produce which had gone onto the market and prevent it from entering the food chain.