Smuggling could also be a carrier to bird flu spread.

Raids at lots of places have revealed smuggled bird and poultry parts or in whole.

In a Chinese grocery store off a piazza, the agents found bags of duck feet. Also a similar raid at a Milan warehouse a few months ago yielded three million packages of chicken meat smuggled from China.

According to experts there is increasing evidence that a thriving international trade in smuggled poultry — including live birds, chicks and meat — is helping spread bird flu.

The (A) H5N1 bird flu virus is robust enough to survive not just in live birds but also in frozen meat, feathers, bones and even on cages, though it dies with cooking. Thus smuggling could cause its spread as well.

In the words of Timothy E. Moore, director of federal projects at the National Agricultural Biosecurity Center at Kansas State University, "No one knows the real numbers, but they are large. Behind illegal drug traffic, illegal animals are No. 2.”

Poultry from bird-flu-infected countries has been banned in Europe since 2002, but smuggling seriously undermines those bans.

"In spite of the E.U. ban, we are still seizing Chinese poultry products," said experts

In early April, Vietnamese health officials said chickens smuggled over the border from China had reintroduced bird flu into their country, which had reported no cases for four months. There is extensive smuggling between China and Africa.

Dr. Juan Lubroth, a senior veterinarian at the United Nations Food and Agriculture Organization in Rome said, "I would love to have a map of illegal trade, but I'm embarrassed to say we don't have a good handle on it. We all know it occurs and we are worried, but what we see confiscated is only the tip of the iceberg."

"We're aware that the risk to public health can be hidden in these containers, but thousands of containers pass through Italian ports and it is impossible to inspect them all. The meat was officially destined for countries on the doorstep of the European Union and we knew that the chickens could be relabeled and illegally re-enter Italy for our consumption," said Mario Pantano, director of the Military Police Health Service in southern Italy, who said his staff had found poultry products stuffed into shoes.

"We believe it is spread by both bird migration and trade, but that trade, particularly illegal trade, is more important. In developing countries, the border controls are marginal at best. As long as there's economic incentive, it will happen," said Wade Hagemeijer, a bird flu expert at the Netherlands-based Wetlands International, which has been studying the role of migrating birds.

The main concern is China, a country with a serious bird flu problem.

In the United States, Dr. Moore, of the Kansas State University, worries particularly about poorly regulated markets in live birds that cater to Muslims and Jews who want poultry slaughtered according to religious custom. Thus, smuggling not only affects economies it would now affect health drastically.