Police also took away vanloads of valuables, including paintings, a $4.2-million clock and fine wines worth thousands of euros per bottle
"France shall, pending a final decision in the case, take all measures at its disposal" to ensure the "inviolability" of a building in Avenue Foch, Paris, described by the African nation as a diplomatic mission, the International Court of Justice (ICJ) ruled.
France disputes that the building is a diplomatic mission.
But the tribunal in The Hague sidestepped Equatorial Guinea's demand to order France to temporarily suspend a corruption trial before French courts brought against the son of its president, saying it would not make any other provisional measures in the case.
Malabo argued the French trial of Teodorin Obiang should be frozen until the ICJ has ruled on its complaint that France has violated Obiang's diplomatic immunity.
Obiang, the 47-year-old son of oil-rich Equatorial Guinea's veteran ruler, goes on trial in France in January on charges of plundering his country's coffers to fund a jet-set lifestyle.
Promoted by his father Teodoro Obiang Nguema to vice president in June, Obiang is accused of using the proceeds of corruption and embezzlement to fund an array of purchases, from a luxury home to private jets and top properties, to pop star Michael Jackson's famous white glove.
In 2012, French authorities swooped on the Obiang family's six-storey mansion on Avenue Foch -- one of the most upmarket addresses in Paris -- seizing it along with a fleet of luxury cars including two Bugatti Veyrons and a Rolls-Royce Phantom.
Police also took away vanloads of valuables, including paintings, a $4.2-million clock and fine wines worth thousands of euros per bottle.
Reading the judgement, vice president Abdulqawi Ahmed Yusuf said the court was "of the view that, pending a final decision in the case, the premises presented as housing the diplomatic mission of Equatorial Guinea at 42 avenue Foch in Paris should enjoy treatment" afforded diplomatic missions under the Geneva Convention.
The court also "rejects the request of France to remove the case" from its workload, Yusuf added.
Obiang's trial will be the first arising from a series of landmark investigations in France into the allegedly ill-gotten gains of a handful of African leaders.