ntenced to 20 years each in 2015, Castany, the two pilots and a passenger on the aircraft were released on bail.
A court in the Dominican Republic upheld a 20-year prison sentence Thursday for a Frenchman convicted of brokering a 2013 plot to smuggle a planeload of cocaine into France.
The judges threw out the appeal lodged by Alain Castany, one of four Frenchmen convicted in the so-called "Air Cocaine" case, ruling his sentence was "logical" and "consistent with the established evidence."
Castany, 70, and his co-accused were arrested at the airport in the resort city of Punta Cana as their small Dassault Falcon 50 jet prepared to take off with what authorities say was a cargo of suitcases stuffed with some 700 kilos (1,500 pounds) of cocaine.
Castany claims he did not know what was in the suitcases.
Sentenced to 20 years each in 2015, Castany, the two pilots and a passenger on the aircraft were released on bail.
The pilots, Pascal Fauret and Bruno Odos, managed to flee back to France. But they were re-arrested and are now under investigation by French authorities.
Castany, who can still lodge one final appeal, is currently in hospital in the Dominican Republic, being treated for injuries sustained when a motorcycle knocked him over last year while he was out on bail.