Vietnamese authorities have launched an extensive investigation into an international diamond smuggling network allegedly responsible for illegally importing more than 28,000 diamonds valued at nearly $11 million, with one of the country’s largest jewellery companies caught up in the high-profile case.

Police say the syndicate smuggled diamonds sourced from India into Vietnam via Hong Kong, using sophisticated methods to avoid customs detection. Investigators allege that the network carried out 141 illegal shipments over several years before distributing the gems to jewellery businesses across the country. Authorities have so far arrested more than 30 suspects, raided over 20 locations, and seized 1,239 diamonds along with jewellery lacking documentation proving its origin.

The investigation also involves Dang Ngoc Thao, the former head of PNJ Laboratory, a gem certification subsidiary of Vietnam’s largest listed jeweller, Phu Nhuan Jewellery (PNJ). Prosecutors allege that imported diamonds were falsely certified after original laser inscriptions were removed and replaced, allowing the gems to be sold as legitimate products. PNJ has denied any corporate wrongdoing, stating the allegations relate solely to a former employee and insisting its certified products remain fully traceable.

The scandal has shaken investor confidence, with PNJ’s shares falling sharply since the investigation became public. Authorities say the probe remains ongoing as they continue tracing the smuggling network’s operations and financial transactions.