The officers were arrived on Deansgate, Bolton earlier on Monday after a reports of a burglary.
On searching the premises they instead found hundreds of cannabis plants.
A Greater Manchester Police spokesperson said: “After a report of a burglary to a property on Deansgate.
“Bolton Town Centre, a cannabis farm containing approximately 300 plants was discovered in the basement.
mages supplied by officers at the scene show the huge number of plants found in the basement.
This comes amid long running concerns about the productions, use and sale of drugs across the borough and Greater Manchester in general but particularly in Bolton town centre.
Several similar cannabis farms have been uncovered in recent months while arrests have been made around Bolton for the possession and sale of illegal drugs.