A group of Florida homeowners filed a class-action lawsuit on Monday against a German drywall maker, its Chinese subsidiaries and several U.S. homebuilders, alleging they put toxic drywall in thousands of U.S. homes.

The lawsuit alleges defective Chinese drywall that emits sulfur gases was used during a building materials shortage at the height of the construction boom and installed in thousands of homes, where it is corroding wiring, wrecking air conditioners and making residents sick.

The lawsuit, which could represent the owners of up to 30,000 Florida homes, names Knauf Gips KG and three Chinese units, Knauf Plasterboard (Wuhu), Knauf Plasterboard (Dongguan) and Knauf Plasterboard (Tianjin), as well as homebuilders Tousa Homes Inc, TaylorWoodrow Communities and South Kendall Construction.

"This may be the worst case of defective houses in history," said Coral Gables, Florida, attorney Ervin Gonzalez, who filed the suit with the U.S. District Court for the Southern District of Florida.

Gonzalez said at least 550 million pounds of Chinese drywall was brought into the United States from 2004 to 2006, the peak of the U.S. housing boom, and up to 60,000 U.S. homes may be affected.

The only way to fix the problem is to move the homeowners out, gut the houses and rebuild the interior, as well as replacing drapes, furniture and other property that may have been contaminated by the gases, he said.