Two international students turned alleged crop sitters have been arrested on Sydney's north shore - one allegedly hiding in the roof of a rental property converted into a marijuana cultivation facility, the other allegedly trying to flee from police.

Officers from the North West Metropolitan Region Enforcement Squad raided two Chatswood houses on Wednesday night, allegedly seizing 436 plants from one and 159 from the other.

Cannabis crops found inside one of the alleged hydro houses.

They arrested and later charged Vietnamese student Manh Tung Pham, 36, and Malaysian student Iven Chun Soong, 23.

The total value of the plants was more than $2 million, police said.