Frustrated by intransigent Chinese drywall manufacturers and government officials, the federal agency investigating the tainted drywall that’s believed to be contaminating thousands of American homes met with Chinese officials this week to urge them to cooperate. Our partners at the Sarasota Herald-Tribune report:

“What we're asking and we've been asking for months is for the Chinese government to help us get the other manufacturers to the table,” said Inez Tenenbaum in a statement sent to the Herald-Tribune from Shanghai, where the CPSC official was meeting in Shanghai with her Chinese counterparts for trade talks on Tuesday.

“Up until today we have not been able to get any Chinese manufacturers to cooperate and we are asking the government to help coordinate that meeting,” Tenenbaum said.

Earlier this week, we reported on efforts by Chinese drywall manufacturers to stonewall the U.S. Consumer Product Safety Commission’s investigation into the source of defective drywall.

Interference by the Chinese government—which owns some of the companies—became apparent when a team of U.S. investigators took a trip to China to inspect several drywall plants. At one point, a Chinese official tried to pry a piece of drywall from the hands of a U.S. investigator. Inspectors met with resistance at every stage of the visit:

Chinese government officials interfered with their investigation by rushing the Americans through inspection sites, blocking their attempts to ask questions and take samples and engaging in a coordinated campaign to intimidate them, the CPSC officials said. At one point, a crowd of employees was ordered to block the entrance to a gypsum mine and encircle the Americans.

… Most of the manufacturing companies the Americans visited refused to disclose even the most basic information about the chemicals they put into their drywall or the manufacturing processes they use. Despite these limitations, the Americans noticed serious quality-control problems at all the plants and mines they visited. The inspectors were so desperate to get samples that they slipped away from their government handlers twice to buy drywall directly from vendors. The vendors said at least one brand of drywall being sold in China smells so bad that contractors refuse to buy it.

Defective drywall—whether from the United States or China—gives off bad odors, poses fire safety risks and has been linked to respiratory ailments, nosebleeds and sinus problems.

The CPSC’s investigation, as we noted, is the largest defective-product investigation ever conducted by the agency, but it has not made much headway in identifying the source of the contamination.

A former CPSC executive director told ProPublica that the tug-of-war with China over the drywall issue “shows that an agency like the CPSC has no leverage to get a foreign government to cooperate if that government doesn’t want to.”

The CPSC and some lawmakers have urged the State Department to put the pressure on China to resolve the drywall issue. The State Department said earlier this year that it had met with a Chinese product-safety minister about the issue and “believes that coming to a fair resolution of this trade-related problem is a matter of great importance to the United States, and should be of similar importance to China.”