Two men and a woman on Tuesday were arrested at a house in Co Armagh on suspicion of producing a class A drug.
Detectives in Lurgan were assisted by officers from the tactical support group (TSG) and ammunition technical officers (ATO), or bomb squad, during the search of the house in Larkfield Square.
The two men, aged 48 and 50, and a 50-year-old woman were arrested and taken into custody for questioning. Police did not identify the drug being produced.
Officers remain at the scene conducting additional enquiries and a further update will be provided in due course, the PSNI said. It is understood the bomb squad were involved in the search as a precautionary measure.