U.S. federal agents have confiscated 40,000 counterfeit condoms imported into San Juan, Puerto Rico, officials said.

SAN JUAN, Puerto Rico (CBS 8) - U.S. federal agents have confiscated 40,000 counterfeit condoms imported into San Juan, Puerto Rico, officials said.

The condoms were seized over a period of five days by Food and Drug Administration and Homeland Security officials and Immigration and customs agents.

They were manufactured in China, according to a U.S. Customs and Border Protection statement Thursday.

Federal officials warned that counterfeit condoms will likely not protect against pregnancy and sexually transmitted diseases, and the materials they are made with can also cause health problems.

“Counterfeit condoms, as well as cosmetics and beauty products, unlike legitimate brands, are not subject to strict quality controls and may contain substances that could lead to long-term health problems,” said the statement from customs. “In the past, seized cosmetics have been found to contain hazardous substances including cyanide, arsenic, mercury, lead, urine and rat droppings.”