Victoria Police have uncovered a sophisticated grow house allegedly containing 500 cannabis plants worth about $5 million.

The large shed located 110 kilometres from Ballarat in Great Western allegedly contained 19 tents full of cannabis plants, in varying growth stages, weighing about 250 kilograms.

Ararat police detectives arrested two people aged in their early 40s on Wednesday after they allegedly left a Brunel Street property, located behind the large shed.

Police allege a water pipe ran from the Brunel Street house directly to the shed, while the house contained tools and tape linked to the hydroponic set-up.

Thu Hien Doan, 42, applied for bail at the Ballarat Magistrates Court on Thursday, while her husband Quang Pham, 43, was remanded in custody.

Police informant Senior Constable Craig Howe told the court the grow house was the most significant set-up he had ever seen.

He said police opposed Doan’s bail application because she was considered a flight risk. But her solicitor said his client was breast feeding her eight month old child, she was an Australian citizen, experienced anxiety and depression and owned a house in Melbourne.

Magistrate Letizia Torres said Doan had shown exceptional circumstances why she should be granted bail, saying all flight risks could be managed.

Doan was released on bail with strict conditions, including reporting to police every day and providing a $5000 surety.

Doan and Pham face drug charges, including trafficking and cultivating a commercial quantity of cannabis.