Customs officers have charged seven people after cracking 25 cross-boundary smuggling cases and seizing $16 million-worth of contraband.

The 12-day operation ending today saw Hong Kong and Guangdong Customs detect 25 cases of cars fitted with hidden storage space being used to smuggle goods through Lok Ma Chau-Huanggang, Man Kam To, Shenzhen Bay and Sha Tau Kok checkpoints.

The operation saw 27 people aged 17 to 70, including a smuggling syndicate leader and 10 drivers, arrested, and goods including electronic products, mobile phones, drugs, wine, petrol and pirated optical discs, seized.

Seven of the arrested have been charged, 15 released on bail and three referred to the Immigration Department.

Customs also shut down the syndicate's Sha Tau Kok goods transhipment venue and two Kwun Tong warehouses, seizing three cars.