Drug cops arrested a 27-year-old man after finding suspected cannabis during a raid in Carshalton.
Police burst into the house in Welbeck Road and found suspected cannabis leaves spread out on a table in an outbuilding just before 9am on Thursday.
Police enter the property
They also found the stumps of plants discarded in the front of the outbuilding.
A 60-year-old woman and a two year old child were in the property at the time of the raid but they were not arrested.
The 27-year-old man was arrested when he returned to the house a short time after the raid.
He was taken to a south London police station on suspicion of possession with intent to supply, cultivation and possession of counterfeit currency. He has been bailed while police analyse the plants found at the property.
Sergeant Ashley Bennetts led the operation after police were alerted by concerned neighbours.
Sgt Bennetts said: "We want to encourage residents to tell us if they suspect drugs cultivation or dealing in their streets. We will treat all such reports seriously and will put a stop to these activities."
Police have asked people to be vigilant and look out for houses emitting a sweet smell, where the curtains are frequently drawn, that get delivery of unusual items like fertilizer and where people come and go at unusual times.