He was hospitalized in Alsace, France for treatment of injuries after being attacked by the men on Monday morning, city police said.
The victim told police he encountered a man in the Rhylounge restaurant in Basel earlier that day whom he later recognized behind the wheel of a car parked on a street in the Kleinbasel part of the city, on the right bank of the River Rhine.
The motorist asked the victim for information on how to get to France.
The Swiss man gave directions before the driver offered to give him a lift to the train station.
When the victim got in the car he was hit on the head from behind and lost consciousness, police said.
He regained consciousness at an undisclosed location in the Alsace region, where he was “abused” on a dirt road by the driver and two other men before being robbed.
The culprits fled in an unknown direction, police said.
The victim was later found by passers-by and taken by ambulance to hospital.
He told police his attackers were North Africans who spoke French and Arabic.
The men, he said, were driving a blue or green Peugeot 206 or 306 with French licence plates and tinted rear windows.
The victim told police the driver of the car was 30 to 35 years old, about 175 centimetres tall, of medium build, athletic looking and weighing around 80 kilograms.
Casually dressed in jeans, sneakers, tee-shirt and jacket, he had a “well-groomed appearance” with short black hair and brown eyes.
The victim was unable to provide a description of the other two men.
Basel police said further investigations are being carried out in cooperation with French authorities.
Anyone with possible information about the crime is asked to contact Basel police on 061 267 71 11.