Immigration officers arrested 20 illegal workers and four employers in citywide enforcement actions on October 11 and 12.
Eight Mainlanders were arrested for breaching conditions of stay by being involved in parallel goods trading at Cambridge Plaza and San Wan Road in Sheung Shui and Lok Ma Chau.
The goods included milk powder, food, skincare products, daily necessities, vehicle components and electronic products.
Twelve illegal workers and four employers were arrested in raids on restaurants, elderly care centres, warehouses, a foot massage centre, a residential building, a construction site and a cement factory.
Since September 2012, 3,070 Mainlanders and 17 Hong Kong residents have been arrested for parallel goods trading. Among the 232 Mainlanders prosecuted, 221 were jailed.