A doctor told police he was travelling almost 200 miles "to buy lamb".
Officers from Dyfed-Powys Police stopped the car that had travelled around 175 miles from London to Brecon on Wednesday.
When approached by officers from the force's roads policing unit in Brecon, the driver, who has been identified as a medical doctor, told them he had made the journey "to buy some lamb".
Lockdown restrictions eased in Wales earlier this week, however, people are still being advised to stay local.
In England, there is no limit on the distance people can travel, but the Welsh Government’s differing rules come into play as soon as someone crosses the border into Wales.
A tweet shared by officers from Brecon's roads policing unit read: "Yet another non essential journey!
"Travelling from London to Brecon is not an essential journey to buy some lamb!
"Also driver is a medical doctor who should know better!"
This comes after a family from Birmingham were fined and sent home after they were caught by police climbing Pen y Fan.
Officers from Brecon roads policing unit saw the family walking down the mountain on a closed footpath.
More recently, Dyfed-Powys Police stopped four vehicles that had travelled from the Midlands to Pembrokeshire to "visit the beaches".
The occupants of two of the vehicles that had travelled from Birmingham to Tenby were unloading beach equipment when police approached them and told them to go home.