Ten people were arrested on suspicion of tobacco smuggling and 50,000 packets of cigarettes were seized by Spanish authorities in two separate incidents in La Línea.
The arrests come after the Spanish authorities stepped up their monitoring of illicit tobacco activity in the region.
In a joint operation by the Guardia Civil and the Policía Nacional, more than 31,000 packets of cigarettes worth more than £100,000 were seized by officers.
A rigid-hull inflatable boat, such as those frequently used for smuggling, was stopped at the beach in the early hours of the morning as the individuals tried to transport the cigarettes.
This followed an event last week when a group of people were spotted unloading tobacco from a vessel moored in the San Barnardo neighbourhood.
A total of 19,000 packets of cigarettes were seized and five individuals were arrested.