Chinese gamblers are using smugglers to avoid pandemic-related travel restrictions in both Macau and on the mainland, according to local police.

On Monday, Macau’s Judiciary Police (PJ) announced the arrest of eight individuals linked to an aquatic smuggling ring that had been clandestinely ferrying mainland gamblers to Macau casinos and back again without going through the normal customs inspections.

A PJ spokesperson said the authorities got wind of this casino version of the Underground Railroad through discussions with their counterparts in Zhuhai, after which a joint operation was launched. Three members of the ring and five suspected customers were arrested in both jurisdictions.

The PJ said the ring and its motorboats had been in operation for at least one month, charging gamblers between RMB22k-30k (US$3,140-$4,280) apiece to make the trip. That sounds pricey, although it also included accommodation in Macau, as registering with one of the casinos’ hotels would have given the game away.