Police say they seized 800 cannabis plants and 17 kilograms of packaged cannabis from the houses.

The Chinese nationals allegedly involved in the grow houses were identified in an investigation into cannabis supply in Canberra and its surrounds that spanned 10 months and involved ACT drug and organised crime squad detectives and their NSW counterparts.

The investigation culminated with raids on homes on Thursday.

Police uncovered the cannabis haul and sophisticated hydroponic set-ups in what appeared to be purpose-built homes.

Zhezhu Quan, 44, and Aifeng Zhang, 51, are suspected of involvement with the Flynn home, where police allege they found 400 plants.

Another two suspects, Manxin Jin, 51, and Chunsheng Li, 48, were arrested in connection with an Evatt grow house.

All four Chinese nationals appeared in the ACT Magistrates Court on Friday before Magistrate Robert Cook.

Prosecutor Amanda Clarke told the court all four were in Australia unlawfully and that immigration agents were sitting in the court watching proceedings.

They were charged with cultivating a commercial quantity of a controlled plant.

Each accused told the court, through an interpreter, that they wished to seek an adjournment for legal advice. No pleas were entered.

Ms Clarke told the court they would be taken to Villawood Detention Centre if granted bail and put on a criminal visa to allow them to stay in the country while court proceedings continued. The group was sent to the Alexander Maconochie Centre and will reappear in court later this month.

A Macquarie man, 42, was arrested and extradited by NSW Police on Friday. A Mawson woman, 43, will be summonsed to court at a later date.