Taiwan’s Department of Health (DOH) announced last week it has once again detected residues of lean-promoting drug ractopamine in beef products imported from the U.S., according to Focus Taiwan News Channel.

Public health authorities at the DOH keep statistics on ractopamine residues and so far they have found 1.9 percent of U.S. beef to contain residual levels of ractopamine, a drug that is approved for use in food animal production in two dozen countries, including the U.S., Canada, and Brazil, but banned by the EU, China and Taiwan.

Focus Taiwan reported that the drug — which promotes leanness and feed efficiency by diverting nutrients away from fat — was recently detected in three batches of U.S. beef products awaiting customs clearance in Taiwan. Local Food and Drug Administration officials said products were ordered to be shipped back or destroyed.

Since July this year, more than 5 million pounds of boneless beef and more than 250,000 pounds of bone-in beef from the U.S. have passed customs inspections, according to the Ministry of Finance.

During that time more than 100,000 pounds of beef imports from the U.S. were banned from entering Taiwan because of ractopamine residues.

Taiwan has said it will maintain its ban on the drug, which is widely used in U.S. beef and pork production, but may consider setting a residue limit of the Codex Alimentarius Commission would adopt one.

The ractopamine ban has become a sticking point in U.S. -Taiwan trade talks.