Knockoff Gucci and Chanel bags were among the goods seized.

GENEVA — Global trade in counterfeit and pirated goods was estimated to be worth $461 billion a year, or around 2.5 percent of global imports in 2013, with American, Italian and French brands the hardest hit, said a report Monday by the Organization for Economic Cooperation and Development and the European Union’s Intellectual Property Office.

The most frequently seized counterfeit goods included footwear, apparel (knitted or crocheted), articles of leather, electrical machinery, watches, medical instruments and non-knitted or crocheted apparel.

The study, which draws on a global set of half a million customs seizures over the period 2011 to 2013, found that counterfeit products originating from China accounted for 63.2 percent of total seizures in 2013 (with China representing 88,324 seizures and Hong Kong, 29,796,) followed by Turkey (3.3 percent), Singapore (1.9 percent), Thailand (1.6 percent) and India (1.2 percent.)

The report also concluded that about 20 percent of the value of seized products refers to intellectual property rights holders registered in the United States, followed by Italy (14.6 percent), France (12.1 percent ), Switzerland (11.7 percent) and Japan, 8.2 percent.

The report estimated that up to 5 percent of goods imported into the European Union in 2013 — which were worth 85 billion euros, or $116 billion — were fakes.

Reflecting the growth of e-commerce and increasing use of the Internet for consumer purchases, the study said that during 2011 to 2013, postal parcels accounted for 62 percent of seizures, air transport for 20 percent and sea transport for 9 percent.

Overall, trademark infringements accounted for 95 percent of seizures, patents and copyright for 2 percent each and design rights, 1 percent.