Police have found up to 2,000 cannabis plants in an Avonmouth warehouse.
Officers attended the building on Jubilee Way at about 9.40pm on March 17 following a report a glass door had been smashed "in what were thought to be suspicious circumstances", say police.
Avon and Somerset police tweeted: "After a security guard noticed a broken glass pane in a door on an industrial unit officers attended and discovered a huge cannabis growing farm.
"The discovery has most certainly disrupted criminal activity and taken a huge amount of cannabis off the street."
A force spokeswoman said the grow is estimated to have comprised up to 2,000 plants, with a street value of approximately £1.5million.
"A scene guard was put in place to facilitate a forensic investigation," she added.
"Enquiries are ongoing and police are keen to hear from anyone with information that could assist their investigation.
"If you can help, call 101 quoting crime reference number 5221057444."
More stories from around Bristol today:
Met Office weather forecast for first week of Rule of Six has some good news
