Test flights of so-called flying taxis - futuristic drones capable of transporting people - have been scrapped in Paris during the Olympics as the certification for the engine has not come through, its promoters told AFP Thursday.

German manufacturer Volocopter has been conducting test flights in the Paris region for several years and had lobbied hard for authorisation from European authorities in time for the Olympics.

The company has partnered with French airport operator ADP, the capital's metro and bus operator RATP, and the Paris regional government.

Certification for VoloCity, the engine conceived and made by Volocopter, had been delayed by a few weeks over its motors, ADP deputy CEO Edward Arkwright said.

"We are a little disappointed, but in any case we had said that we would not make any compromises with security," he added.

Volocopter CEO Dirk Hoke said the delay was due to "an American supplier who was not capable of providing what he had promised".

He said the motors would be sent back to France next week but not in time for the test flights to be held in Paris before the Olympics close.

Initially, test flights had been due to take place during the Games, landing on a float on the Seine near the Austerlitz railway station in southeastern Paris.

The promoters had hoped to use the global draw of the Olympics to show that the technology could efficiently link "vertiport" take-off and landing sites.

However test flights without passengers will be held in the aerodrome of the suburban town of Saint Cyr l'Ecole, west of Paris, on Thursday and Sunday, they said.

The town is close to the Chateau de Versailles where Olympic equestrian events are being held.

Backers tout flying taxis as a low-carbon form of aviation and hope future larger versions could be used as ambulances or in other roles.

However, many city officials in Paris have derided the plans as harmful to the environment.

 - AFP Relaxnews