The four Vietnamese, including a 17-year-old boy and his mother, were arrested on June 20 after police officers swooped on two brick homes on Baxter Street.

The early-morning raid allegedly uncovered “substantial” stashes of cannabis plants at various stages of growth worth thousands of dollars.

The 17-year-old boy pleaded guilty at a Children’s Court on Thursday to one count of cultivating a commercial quantity of cannabis.

His 36-year-old mother pleaded guilty via video link at the Ballarat Magistrates Court to the same serious charge but her hearing can only be held in the County Court.

A police prosecutor told a Children’s Court the teenager lived at the Baxter Street property with his mother when Ballarat Divisional Response Unit detectives uncovered 80 cannabis plants weighing almost 80 kilograms.

“Police found a sophisticated hydroponic set-up in four rooms,” the prosecutor said.

“Each grow room was professionally modified with fake plaster walls, lighting with heat lamps, watering systems, fans and 80 plants in varying maturity.”

The court was told there were three separate electricity bypasses set up at the property and $3279 worth of electricity was stolen over 69 days between April 12 and June 20.

The teenager’s barrister told the court his client, who arrived in Australia five years ago on a student visa, was dependent on his mother.

“He doesn’t have an influence on his mother and what she should be or should not be doing,” the barrister said.

“The mother was a sitter. She was told what to do, she was given a job and she got paid for it.”

The magistrate agreed the teenager was under the influence of his mother and sentenced him to 92 days in a youth detention centre, which he has already served.

Anh Luu, 22, and Trong Vu, 33, also fronted the Ballarat Magistrates Court on Thursday over the raids at the grow houses. They will reappear in court later this year.

The arrests in June came after a long-running investigation into clandestine cannabis growers across the Ballarat region.

Ballarat police teamed up with Melbourne-based drug squad detectives to execute the raids.