(IDEX Online) - Customs officers in Hong Kong made their biggest diamond seizure for three years at a crossing point into mainland China.The driver of a truck destined for Shenzhen was found to have 160 gems worth $840,000 stuffed into a trouser pocket. Criminals try to smuggle diamonds from Hong Kong to factories across the border to avoid paying import taxes of up to 20 per cent.In this case the gems were recovered during a routine inspection at the Heung Yuen Wai control point.It was described as "the largest bust of its kind in three years" in a report in the South China Morning Post.It said a 33-year-old man was arrested on suspicion of attempting to export unmanifested cargo. A suspected accomplice was also detained later.The offence carries a maximum penalty of seven years in jail and a $260,000 fine.Pic shows approach road to the Heung Yuen Wai control point.