Mamoudou Sare, a 37-year-old labourer from Burkina Faso, was killed on Monday evening in Lucera, in Italy's southern Puglia region.
He was reportedly spotted by farmer Ferdinando Piacente, 65, and his 27-year-old son Raffaele trying to steal melons from their land along with two accomplices.
The two Italians decided to confront the three and a scuffle broke out, during which the younger Piacente's nose was injured, SkyTG24 reported.
His father allegedly began shooting at the three men with a shotgun as they fled the scene, following them as they drove off in a Fiat car.
Ferdinando Piacente reportedly continued shooting at the men as he chased them in his SUV, forcing the Fiat to stop. At which point the farmer continued shooting, hitting Sare in the back and Adam Kadago, also from Burkina Faso, in the chest.
A third man who was not identified survived uninjured and provided his eye-witness account to the police, SkyTG24 said.
The farmer is being held in police custody with his son, who could also face charges over his alleged involvement in the shooting.
Immigrant farm labourers in southern Italy are frequently forced to work extremely long hours for just a few euros a day, often working under crime bosses who profit from the system.
But such mistreatment does not only affect foreigners; one Italian woman died while working in a field last month, reportedly after telling her employer she felt unwell. A Tunisian man and a Sudanese man were also reported to have died in the fields of Puglia over the summer.