Environmentalists and consumer advocates urged the government Thursday to increase testing of farm-raised salmon from Chile after authorities in Germany detected banned chemicals in Chilean fish.

"We obviously have a problem, at least according to German government data," said Urvashi Rangan, a senior scientist with Consumers Union, a nonprofit consumer advocacy group. "Some of these banned substances are potentially carcinogenic, and the only way to find out how widespread it might be is for the Food and Drug Administration to get out there and start testing."

Salmon is one of the top seafood items on American menus. Most of it is farm-raised as part of a global industry, and Chile is a leading supplier. The $2-billion-a-year Chilean industry is in crisis over an outbreak of a virus that can kill salmon but is harmless to humans.

Earlier this month, a German consumer protection agency detected antifungal and antiparasitic chemicals that are banned in Europe and the U.S. in samples of Chilean salmon. Environmentalists are also concerned about the use of antibiotics to keep penned-in fish from getting sick.