Police were called after reports that a consignment had been contaminated at a factory in Lisburn, County Antrim.
The incident involved a shipment of empty cans that were delivered to the factory ahead of being filled and sealed.
Coke insisted the issue was identified ‘immediately’ and had no impact on its products on sale.
A spokeswoman said: ‘At Coca-Cola, we take the safety and quality of our products extremely seriously.
‘We are aware of an incident involving empty cans at our plant in Knockmore Hill, Lisburn.
‘We are treating this matter extremely seriously and are conducting a thorough investigation in co-operation with the Police Service of Northern Ireland (PSNI).
‘The problem was identified immediately through our robust quality procedures and all of the product from the affected batch was immediately impounded and will not be sold.
‘This is an isolated incident and does not affect any products currently on sale.’
A PSNI spokesman said: ‘Detectives are investigating an incident at commercial premises in the Lisburn area following reports that a consignment of containers delivered to the premises had been contaminated.
‘The investigation is at an early stage and there are no further details available at this time.’
The Foods Standards Agency in Northern Ireland confirmed it was aware of a ‘physical contamination incident’.
‘There is no evidence to suggest that any affected product has reached the market,’ said an FSA spokeswoman.
‘The incident is subject to an investigation by the PSNI and the environmental health unit of Lisburn and Castlereagh City Council.
‘The FSA in NI cannot comment further in order not to jeopardise that investigation.’