An investigation is currently underway looking at whether Chinese antibiotics seized at a UK airport last week were meant for a poultry farm in Northern Ireland.
A Co Tyrone farm which supplies poultry giant Moy Park was searched by officials and items were seized.
The Guardian reported that the medicine, believed to be the antibiotic amoxicillin from China, was intercepted at an airport last week.
Approved for strict veterinary use in the UK, amoxicillin, which has restricted imports, is only supposed to be used under veterinary supervision.
Antibiotics can also be used as a growth promoter to reduce the amount of feed birds take to get the slaughter weight down.
Northern Ireland's Department of Health (DoH) is heading the investigation, which is currently ongoing.
“A multi-agency operation was carried out on Thursday in the Co Tyrone area in pursuance of offences under the Human Medicines Regulations 2012 and the Veterinary Medicines Regulations 2013,” a spokesperson said.
“A number of items were removed for examination.”
The Food Standards Agency (FSA) added that it is working to ensure the food chain has not been compromised.
Moy Park, which supplies some of the UK's biggest retailers, said the farm was an 'independently owned, contract supply farm.'
A spokesperson said: “This matter is being investigated by the relevant authorities and we believe it is an isolated incident.
“Any breach of the strict regulation on the use of veterinary medicine is unlawful and completely unacceptable to us.”