The hash-dealing family included a 50-year old mother, her two sons — aged 31 and 33 — and her 38-year-old nephew, all of whom have been arrested by local police.
Police said the family ran "one of the active distribution points in the town", reported the news site La Nueva España.
Neighbours said the drug-dealing household received a stream of visitors, usually in the evening.
Many of these customers were underage, said the neighbours.
Police explained the family business was run by a "boss" but did not specify who this was.
They said this key figure usually sold the hash and the other members of the household helped out when that person was sleeping or out.
The police investigators found 1,100 "doses" of hashish, reported La Nueva España.