Three people from different households in England were stopped by police whilst travelling in the same car on a 500-mile trip across Wales.
Police stopped the car on its way to Snowdonia National Park on Tuesday, with the passengers claiming they were on a "sightseeing" trip.
Officers from Dyfed-Powys Police stopped the vehicle in Builth Wells and issued four fixed penalty notices to the occupants before sending them home.
It comes as police across the country continue to monitor traffic, using checkpoints to query people's reasons for travel during the coronavirus pandemic.
Last month there were reports that the Welsh Government was going to increase the fines for individuals who breach the 5-mile rule during lockdown.
At the beginning of June, officers stopped numerous vehicles from England that were making their way to parts of Pembrokeshire to 'visit the beaches'.
Lockdown restrictions in Wales have been eased slightly by First Minister Mark Drakeford, but there are still different rules to England.
Despite the changes, the regulations still make it clear that people should not travel excessively and that they should ideally only travel within five miles.