Police seized 110 cannabis plants following a raid on two houses in Prescot.
Officers stormed properties in New Cross Street and Kemble Street during dawn raid which resulted in scores of plants being discovered.
The haul uncovered at the New Cross Street house had an estimated street value of £176,000.
A 26-year-old man from Prescot was arrested on suspicion of production of cannabis after a second farm was discovered in the attic of a house on Kemble Street.
He is currently being questioned by detectives at a police station in Merseyside.
Officers found plants growing in all three floors of the New Street address, and 10 plants in the loft of Kemble Street.
Insp George Phillips said: “We take the production of cannabis very seriously. While it is often perceived as a harmless drug it causes huge problems for our society and we are determined to bring those involved in this drugs trade to justice.
“Cannabis has a very disctinctive smell and we ask anyone who may have any information about the drug being grown to contact us so we can take action against those responsible.”
Anyone with any information about cannabis being grown in Prescot is asked to call Merseyside Police on 101, or Crimestoppers, anonymously, on 0800 555 111.