US: A Florida federal investigation into defective plasterboard imported from China has broadened to include US-made product, said Associated Press.

US: A Florida federal investigation into defective plasterboard imported from China has broadened to include US-made product, said Associated Press.

Reports of tainted Chinese-made plasterboard surfaced last year, and homeowners who bought houses built with imported materials have filed hundreds of lawsuits against builders, suppliers, and manufacturers.

In a report issued last Monday, the Consumer Products Safety Commission said its studies found a "strong association" between the Chinese-made plasterboard and corrosion. But, sporadic reports are also surfacing of problems with American-made material.

The faulty material is claimed to have levels of cellulose but test results so far have been inconclusive.

The US-imported large quantities of Chinese-made gypsum board during the recent housing boom when domestic building materials were in short supply.