Twenty people have been arrested by police in Shanghai, Beijing and Guangzhou in connection with the smuggling of diamonds worth 40 million yuan (US$6.15 million), Shanghai Customs said yesterday.

The customs’ anti-smuggling bureau said the gang had been buying diamonds from an overseas website since July last year for delivery toHongKong.

It said they were then hidden in other goods and illegally imported into the Chinese mainland without declaration or paying tax.

More than 250 diamond products and 187 bags of small diamonds were seized and investigations are ongoing.