Four people were arrested after a large cannabis factory was discovered at a house in Wisbech at the weekend.
Around 70 plants, thought to be worth tens of thousands of pounds, were discovered at a property in Seabank Road shortly before 2am on Saturday.
Police had been searching for a missing person in the area when the drugs were discovered.
A Cambridgeshire Police spokesman yesterday said a man in his 20s and a woman in her 40s, both from Wisbech, had been arrested on suspicion of being involved in the production of the class B drug.
They were both later released on bail to report back to officers on March 22.
Another man, also in his 20s, and a teenage boy were also detained on suspicion of being involved in the production of cannabis and cultivating cannabis.
Both were later released with no further action being taken against them.
The plants, which police believe could be worth up to £60,000, were seized.
A Twitter post from the Fenland police account on Saturday morning revealed the factory had been discovered while Norfolk Police were searching for a missing person in the area. The force later confirmed officers had been looking for a teenage girl who was found safe and well.
The incident is the latest in a string of cannabis seizures made by police in the Fenland area in recent months.
A number of plants were recovered during a search operation in the district last month, while a further 190 plants were found following a fire at a disused restaurant in Norwood Road, March, over Christmas.
Last September, a £600,000 haul of the drug was discovered at a warehouse in Friday Bridge.
That came just 10 days after nearly 200 plants, with an estimated street value of £100,000, were seized from a property in Princes Road, Wisbech.