France seized the cars belonging to Teodoro Obiang Nguema's family – including a Maserati, a Ferrari and a Rolls Royce – as part of an investigation by two judges into French properties of three longtime African rulers.
The cars reaped €3.21 million, auction house Drouot said in a statement.
A red 2010 Bugatti Veyron 16.4 Grand Sport with just 1,209 kilometres on its odometer went for €914,816.
A white and blue 2007 Maserati MC 12, which had clocked just 2,328 kilometres, went for €731,853.
A yellow 2010 Ferrari 599 GTO, which had run for a paltry 597 kilometres, sold for €277,875.
Other cars sold included another Bugatti Veyron, two Bentleys, a black Rolls Royce Phantom, a yellow Porsche Carrera 980 GT and a Mercedes.
The Obiang family had appealed the seizure of its luxury cars after they were taken in September 2011.
But in a ruling in November 2012, a French appeals court cited "sufficient indications to believe that all the vehicles were acquired through the misappropriation of funds", according to an article in French daily Le Monde.
In February, authorities also seized the family's six-storey mansion on the chic Avenue Foch in Paris, carting away vanloads of possessions including paintings by famous artists, a clock worth an estimated €3 million and wines worth thousands of euros a bottle.
The investigation was launched in December 2010 to determine whether Congolese President Denis Sassou Nguesso, late Gabonese president Omar Bongo Ondimba, and the Obiang family used corrupt means to acquire their expensive properties in France.
French authorities have also issued an arrest warrant for Teodorin Obiang, the leader's son and vice president. Obiang's office protested that the warrant "seriously infringed" on international law.
In September, Equatorial Guinea asked the International Court of Justice to order France to end the graft probe.