Hartlepool Neighbourhood officers seized over 300 cannabis plants, worth more than £400k when they raided a property on Stockton Road in the town this morning.
Six people - a 30-year-old woman, a 33-year-old man, a 34-year-old man, two men aged 35 and a 48-year-old man - were arrested on suspicion of conspiracy to produce cannabis and taken to police custody for questioning.
Inspector Adrian Dack of the Hartlepool Neighbourhood Policing Team said: "It's a fantastic result, to seize cannabis of this value and remove it from trade on the streets of our town.
"Operation Sycamore is an intelligence-led operation, aimed at targeting those producing and dealing drugs in Hartlepool, and making our communities a safer place to live.
"We welcome information from the public, and anyone who suspects drug activity can let us know about it by calling 101."