Tees, knits and minis sporting the Abercrombie & Fitch logo were flying off the shelves at nine London stores earlier this year — and Abercrombie officials were furious. “We don't have any stores in the U.K.,” explains Thomas Lennox, spokesman for the Ohio-based retailer.

In response, the company is working with British customs agents to raid stores and seize suspicious shipments. Investigators are also putting the heat on the nine already identified sellers to reveal who made the counterfeit apparel. “It's a significant problem,” Lennox says. “We're talking about thousands of units.”

Nancy Kratzer, director of the Washington, D.C.-based National Intellectual Property Rights Coordination Center, says the growth of knockoffs is staggering. “It's now estimated that 5 percent to 8 percent of all goods sold worldwide are counterfeit.”

The center is the U.S. government's latest weapon in the fight against counterfeiters. Under its auspices, FBI and U.S. Immigration and Customs Enforcement (ICE) investigators use search warrants, electronic intercepts, wiretaps and go undercover for international probes. “Before, all we did was try to seize goods,” says Gary White, chief of ICE's commercial fraud unit. “Our goal now is to dismantle smuggling operations.”

U.S. Customs & Border Protection made 6,500 seizures of counterfeit merchandise last year. The knockoffs were worth an estimated $94 million, officials say. Among the seized items were mountains of apparel valued at $14 million; handbags, wallets and backpacks valued at $11.5 million and DVDs and other media valued at $7.3 million.