A FOURTH hydroponic cannabis crop has been found growing in a Portland building, with police swooping to arrest two men at the scene and seize 170 plants on Tuesday.

The mature crop was found as part of Operation Highrise, a Victoria Police effort to stamp out the growing of cannabis in the south-west, however in a change of approach, the latest plants were found in a rented industrial shed rather than a fully-owned house.

Detective Senior Constable Jarrod Anderson said following a long-running investigation eight detectives and uniformed police from Portland and Hamilton entered the Kunara Cres shed at 1pm on Tuesday and arrested a 27-year-old and a 31-year-old man, both from Vietnam.

The men were living in Melbourne, however one is alleged to be staying in Australia unlawfully and the other is on a student visa.

They required an interpreter when being interviewed by police on Tuesday.

Cannabis plants were found growing in sophisticated rectangular structures that were brought into the building and set up on the ground and mezzanine levels.

Extensive lighting and exhaust systems were powered by illegally-sourced electricity that would usually have cost about $20,000.

The shed windows had been covered to block out the 24hr light inside, raising the suspicions of police.

Detective Senior Constable Anderson said the setup could have been there for a few months.

Victoria Police forensic botanists were on scene to study and remove the plants on Wednesday; they will eventually be destroyed.

Kunara Cres is one of Portland’s busy industrial and retail thoroughfares, backing onto residential streets in South Portland.

The men appeared in the Magistrates’ Court on Wednesday where no application for bail was made.

They have been charged with cultivating a narcotic plant, with investigations ongoing about potential commercial quantity charges.

They have been remanded in custody and will reappear in the Warrnambool Magistrates’ Court for a committal mention on December 4.

Nine hydroponic growing setups or drying houses have been found in the region in the past year, with three houses in South Portland found to be hosting similarly sophisticated operations between April 25 and May 19.

Operation Highrise also found cannabis operations in Grassmere, Horsham, Hamilton and Warrnambool.

People of Vietnamese background have been arrested in relation to most of the incidents.

About 1000 plants were seized following the three Portland searches.

Anyone with any information about suspicious activity can contact the Portland police on 5522 1500 or Crime Stoppers on 1800 333 000; people can also make a report online by going to www.crimestoppersvic.com.au/report-a-crime.