The immigration police discovered 38 Chinese construction workers living in a complex that included underground rooms in the Holon industrial area on Thursday.
Officers raided the site after being tipped off that the workers - eight illegal and 30 legal - were living behind what appeared to be the door of a refrigerator, immigration police spokeswoman Orit Friedman said.
The policemen had to crawl through the bottom part of the fridge to access the living area, which also led to the underground rooms.
"You open a fridge and see there is a room. You then open another door and another door and eventually you discover five or six people," she said.
The workers were living in what Friedman described as "terrible conditions." The illegal eight are now set to be deported as part of the government's crackdown on the use of foreign labor.
In 2005, the government deported 6,526 workers but allowed 936 to stay after finding other employers for them. The deportation number was 60% below the 2004 figure, a change that the immigration authorities attributed mainly to disengagement.