A 34-year-old man has been charged with cultivation of cannabis, possession and possession with intent to supply.
The charges relate to the seizure of more than 400 cannabis plants in Bangor, County Down, on Thursday.
Officers from the area’s district crime team raided a house on Raglan Road and found plants with an estimated street value of about £500,000.
Equipment for use in the cannabis production process was also seized during the operation.
The plants were all in the early stages of growth, police said. A man aged 34 was arrested by the police and is being questioned.