WASHINGTON (CNN) -- Federal drug officials say they've arrested 124 people and busted 56 labs in the largest illegal steroid investigation in U.S. history.



The Drug Enforcement Administration says it busted 56 steroid labs in 27 states.



The 18-month investigation, dubbed "Operation Raw Deal," targeted traffickers who allegedly imported raw materials from China and used them to make anabolic steroids, human growth hormone and insulin growth factor, the Drug Enforcement Administration said.



"Today we reveal the truth behind the underground steroid market: dangerous drugs cooked up all too often in filthy conditions with no regard to safety, giving Americans who purchase them the ultimate raw deal," DEA Administrator Karen Tandy said in a statement.



Authorities made arrests in 27 states, including busts in Los Angeles, California; New York City; San Diego, California; Providence, Rhode Island; and Kansas City, Missouri.



They seized more than 530 pounds of raw materials and 11.4 million steroid dosage units in the United States, officials said, enough to supply hundreds of users.



Most of the arrests were made between Thursday and Sunday, the DEA said.



Chinese authorities cooperated with the investigation, which targeted 37 companies in China, the DEA said.



So far, one Chinese lab has been shut down, officials said.



The Chinese "have done everything" they were asked to do, said DEA spokesman Rusty Payne.  Watch DEA officials say bust is only the beginning »



The operation, according to the DEA, also cracked down on underground trafficking of counterfeit medications as well as Web sites that were distributing materials that helped in converting raw steroid ingredients into the finished product.



"DEA successfully attacked the illegal steroid industry at every level of its distribution network-from the manufacturers in China who supply the raw materials, to the traffickers in the United States who market the deadly doses," the DEA statement said.



Besides China, other countries which cooperated in the operation included Mexico, Canada, Belgium, Australia, Germany, Denmark, Sweden and Thailand, officials said. E-mail to a friend
From which country were raw materials imported? How many labs were shut down? where Authorities arrest 124 people, shut down 56 labs? How many people where arrested? How many people did authorities arrest? where Investigators seize raw materials imported from?
China 56 in 27 states. 124 124 China
question: From which country were raw materials imported?, answer: China | question: How many labs were shut down?, answer: 56 | question: where Authorities arrest 124 people, shut down 56 labs?, answer: in 27 states. | question: How many people where arrested?, answer: 124 | question: How many people did authorities arrest?, answer: 124 | question: where Investigators seize raw materials imported from?, answer: China