European Commission experts were expected to arrive in Poland on Monday on a five-day visit to probe the illegal slaughter of sick cattle for the beef market.
The European Commission said last week that meat from such illegal practices in Poland had been uncovered in 13 other countries.
The Polish ministry of agriculture has said that it has closed down the slaughterhouse at the heart of a scandal.
Poland’s agriculture minister has warned that offenders should expect “no leniency”.
Jan Krzysztof Ardanowski has admitted that such illegal practices dented confidence in Poland’s food producers, adding that police were investigating.
The European Commission probe comes in the wake of an expose by Polish private broadcaster TVN, which reported that a plant in east-central Poland had processed meat from sick cows and animals that were dead before slaughter.