The Hague, The Netherlands-Thieves recently attacked Edwin Legebeke's supermarket, but this is not an ordinary shoplifting. The criminals absconded with an unlikely but very precious bounty: a dozen barrels of milk powder.

“One of them distracted me, the second kept the cashier busy, and the third took the goods,” said Legebeke, who owns the store in Doetinchem, a small town 80 miles southeast of Amsterdam. "It drives me crazy."

Dutch infant formula is a very precious commodity in China. In the black market boom, Dutch shelves have been sold out. Lisette van Bale, a spokesman for the Dutch police, said there were 900 formula thefts last year. "Demand is greater than supply, which brings lucrative deals for criminals."

The battle for Dutch dairy products can be traced back to 2008, when the Chinese government revealed that one of the country’s largest dairy producers had been diluting formula milk powder and adding melamine, an industry used to make plastics and adhesives. Compound. Six children died of kidney failure, another 53,000 were hospitalized for kidney damage or other diseases, and an estimated 300,000 people were sick.

After the scandal, consumer confidence in Chinese infant formula collapsed, and mothers began to import large quantities of milk powder. Soon, Chinese tourists and Dutch residents with relatives in China began to mail or carry milk powder produced by a trusted Dutch brand on flights to the world's most populous country.

The Netherlands is not the only country affected by the surge in demand for infant formula from China. Dairy products in Ireland, Denmark and New Zealand have all felt the impact of market implosion. But Peter He, an expert on Chinese economics at Delft University of Technology, said that dairy products from the Netherlands, the fourth largest dairy producer in Europe, enjoy a special place among Chinese parents.

The country is also a major international transportation hub, ideal for traders looking for cheap delivery of milk to China or hiding it in other products shipped to the East. "It's about combining the excellent transportation and logistics of the Netherlands with the big brands that are well-known in China," He said.

The Dutch dairy industry tried to set up a production line in China, but Chinese consumers did not trust formula milk powder with the "Made in China" label. In the last three months of 2014, the Dutch National Post Company reported that it had sent 600,000 packs of infant milk powder to China.

Unable to meet the demand, Dutch retailers adopted rationing measures. Some stores limit sales to one or two packs of formula milk powder per customer. Others set minimum purchases of other groceries to discourage hoarders. Managers scribbled "No Resale" or crossed out the ingredient list on the formula container to prevent the operation of specific brands.

Restrictions are not always effective: Stores report that frustrated customers turn to violence. “On average, we receive three to four reports of verbal and physical assaults every week,” said Henk Baars of GIO, a liaison organization between the retailer and the police. "Employees are verbally abused, thrown with products, punched and kicked or spit."

He said that since the price of formula milk powder in China is up to five times the price in Dutch shops, organized criminal activities have been involved. "Obviously, there are a lot of people involved and it's very well organized," he said. "There are various trade routes, but what form they take is largely unknown. It's hard to say because this is a secret market."

The Dutch police said they intercepted trucks on the highway full of milk powder containers, sometimes carrying large amounts of cash.

Retailers called on the authorities to take more measures to curb illegal trade. Suzanne van de Graaf of Detailhandel Nederland, a retail trade association, said: "We have urged the police to treat these crimes as organized crime, not shoplifting, so the perpetrators will not only be warned and put back on the street."

Van Bell said that the police are pursuing criminal responsibility in accordance with the law. "When an illegal act occurs, we will consider the severity-such as shoplifting or robbery-which determines our handling." She said.

Earlier this year, the EU abolished milk quotas, a move that may boost exports from the 23 EU member states and enable European dairy producers to meet Chinese demand. But before these dynamics change, the milk powder black market and related crimes may continue to exist, He said.

"Western production is too small to meet China's huge demand," he said.