The top court will rule Wednesday in a tense diplomatic row between Equatorial Guinea and France, after a French court found the African nation's vice president guilty of embezzling millions to fund his lavish lifestyle.
Malabo has accused Paris at the International Court of Justice (ICJ) in The Hague of violating international conventions on diplomatic relations and immunity by prosecuting the president's son, Teodorin Obiang, for plundering his country's coffers.
The 48-year-old son of Equatorial Guinea's President Teodoro Obiang was tried in absentia by a Paris court and given a three-year suspended sentence in October for corruption, for embezzling 150 million euros ($180 million) of public money.
He was also handed a suspended fine of 30 million euros ($35 million) for money laundering, corruption and abuse in the small central African state.
But Malabo has taken its case to the ICJ accusing Paris of violating Teodorin Obiang's diplomatic immunity. It also alleges that French officials had no right to raid the Obiang family's six-storey mansion on Avenue Foch in Paris.
In 2012, French authorities seized the property, on one of the French capital's poshest streets, along with a fleet of luxury cars including two Bugatti Veyrons -- often dubbed the world's most expensive supercar -- and a Rolls-Royce Phantom.
Police also carted away vanloads of valuables, including paintings, a $4.2-million clock, Michael Jackson memorabilia and fine wines worth thousands of euros per bottle.
Malabo contends the mansion in the luxury 16th arrondissement, which boasts a cinema, spa and gold-leafed covered taps, is its embassy in Paris, and as such off-limits to French raids.
Equatorial Guinea sees the case as "a flagrant violation which has given rise to deep indignation in my country," Carmelo Nvono Nca, Malabo's ambassador to the Netherlands, told a court hearing in February.
He maintained that Paris was showing "indifference" to his country's "sovereign rights".
But France hit back that Equatorial Guinea was only resorting to the ICJ in the hopes of paralysing the legal case against Obiang in France, and maintains the Avenue Foch address was never registered as the embassy.
The ICJ has already found once in favour of France, refusing Equatorial Guinea's call to order a halt to the French legal proceedings.
President Teodoro Obiang Nguema, 75, has ruled Equatorial Guinea with an iron fist since 1979, making him the world's longest-serving president of a country awash with oil, but mired in poverty and a reputation for corruption.
He appointed his son as vice president in June 2016 -- two years after the first charges were first brought in France.
The case sets a precedent for France which has long turned a blind eye to African dictators pouring their ill-gotten gains into Parisian real estate and luxury products.
French judges have also been probing allegations of corruption against Republic of Congo President Denis Sassou Nguesso, and Omar Bongo, the late president of Gabon.