Several Chinese companies were promoting equipment banned by the EU when Interior Minister Gérard Collomb opened the fair on Tuesday, according to Amnesty International.
One, Origin Dynamic, was displaying a bracelet and a jacket, both of which could give the wearer electric shocks, the NGO's Aymeric Elluin told Le Monde newspaper.
Its catalogue also offered potential customers an anti-riot fork that can give electric shocks.
Four other Chinese companies listed products such as foot-chains and spiked truncheons, Elluin said.
The import and export of instruments of torture is banned by the European Union and their display and promotion has been forbidden since 2016.
"The equipment had been removed by Thursday when I visited Milipol," RFI's Jan van der Made said. "There were 20-30 stalls from China, including Norinco, a subsidiary of the People's Liberation Army."
The fair's organisers said that the equipment must have escaped the notice of their controllers.
The stall displaying the electronic bracelet has been closed and stallholders have been told to withdraw the catalogues listing banned objects.