The Soviets and the CIA reportedly used it as a truth serum during the Cold War. The drug's chemical make-up induces powerful hallucinations and in strong doses it is lethal.
Paris's judicial police believe the Chinese suspects administered the substance on "dozens" of victims, in the first reported case of such a crime.
It is thought the three suspects are part of a triad-style gang running a multi-million-euro global operation.
"The victims targeted, very often old, were accosted in the street by a first woman," a source close to the investigation told Le Parisien.
"This person claimed to be looking for a mysterious 'Doctor Wang' before being joined by her accomplice. They managed to isolate their victims, then got them to breathe in a mixture of plants on the grounds they had powerful curative qualities - even protecting them from misfortune."
All the victims recounted falling into a kind of "hypnotic state under the total sway of their handlers", said the source.
The pair had reportedly been operating since spring in Paris.
They were caught last month at the entrance to a metro station after they were identified by a friend of one of the victims. Both deny wrongdoing.
In a raid on a hotel room, police discovered an array of vials including "various Chinese medicinal substances as well as weighing scales, filters and gloves".
Analysis of the substance is under way. A third suspect, who is 56 and is thought to have prepared the drug, was also arrested.
Chinese authorities informed French police that the trio belonged to a notorious criminal network, which "specialises in mental submission with the aid of unknown products".
Miriam Gutierrez, a toxicology expert in Bogota, Colombia, said: "From a medical point of view, it's the perfect substance to commit criminal acts because the victim won't remember anything, and therefore won't report anything."
- Daily Telegraph
