Shenzhen customs has busted a cross-border syndicate that allegedly smuggled 700 million yuan (HK$795 million) worth of bird's nests from Hong Kong and sold them to hundreds of mainland retailers in 40 cities, mainland newspapers reported yesterday. Customs officials said the gang, headed by Hong Kong and Shenzhen residents, hired more than 200 smugglers to transport a total of 28 tonnes of cliff-swallow nests from Hong Kong to Shenzhen between 2007 and last year, evading 226 million yuan in taxes, the Southern Metropolis News reported. The report described the bust as the biggest bird's-nest-smuggling case of the past six decades. The authorities arrested 19 people, most of them from two families in Hong Kong and Shenzhen. Police said mainland buyers first placed orders with Hong Kong retailers, then the gang's ringleaders bought the bird's nests and got the smugglers to take the contraband across the border. Once on the other side, the delicacy was mailed out to the mainland buyers. Customs authorities said at least 80 Hong Kong retailers and another 480 mainland buyers from 40 cities in 15 provinces were involved in the case. Customs officials said the gang was highly organised, with daily meetings and training on smuggling skills and its own system for rewards and punishment. Smugglers were required to monitor customs officers closely and used mobile phones to report any unusual circumstances. If one smuggler was detained, the gang would suspend all scheduled smuggling that day to avoid further losses. Smugglers were also taught to avoid fixed routes and frequently change buses to cover their tracks. Those in the business said the smuggling of tonic ingredients such as bird's nest was rife because tariffs on the mainland were higher than in Hong Kong, the report said. 'Mainland customs levies heavy taxes of nearly 50 per cent on the nests, but swallow's nests in Guangdong cost only a little bit more than in Hong Kong,' a retailer said. Though the mainland imports only a limited quantity of bird's nests every year, one market in Guangzhou alone sells 20 tonnes annually, the retailer noted, suggesting that most of the nests available in the province must have been smuggled.