One of the matters involving Mr. Bolloré now under scrutiny is connected to Alpha Condé, a Guinean politician who is believed to have befriended Mr. Bolloré while he lived in political exile in Paris in the mid-2000s.
After Mr. Condé returned to Guinea to seek the presidency in 2010, an international Havas unit helped guide his campaign, and then allegedly underbilled him for its services. After Mr. Condé won, the Guinea government transferred an agreement to run the container-port terminal at Conakry, Guinea’s capital, to the Bolloré Group from a French rival.
The deal, first reported by the French newspaper Le Monde, added a strategic jewel to the Bolloré Group’s network of assets in West Africa, where it has a virtual stranglehold on much of the transporting of billions of euros worth of cargo. A map of the group’s holdings shows a web of Bolloré-run roads, railways, waterways, airports and ports that covers two-thirds of the continent and employs more than 25,000 people.
A similar pattern emerged in Togo, another former French colony. There, the same Havas unit was said to support, with below-market-rate services, the re-election of President Faure Gnassingbé in 2010.
A few months before Mr. Gnassingbé, who has close ties to Mr. Bolloré, won a second term, his government awarded a contract for the container port at Lomé, the country’s capital, to the Bolloré Group.
In its statement on Tuesday, the Bolloré Group said it had originally gotten a contract to operate the port in 2001, long before Havas was doing business in Guinea. In 2013, Havas stopped doing political consulting for French and African figures after some of its clients, including the former International Monetary Fund director Dominique Strauss-Kahn, became ensnared in scandals.
The Bolloré Group has routinely sued French and African media outlets for defamation over reports on its business dealings on the continent. Journalists at Canal+, a French television channel owned by Vivendi, have accused Mr. Bolloré of using his influence to try to suppress an investigative report about a popular revolt against Mr. Gnassingbé in Togo. Two producers were fired after the report aired in December.
The suits have challenged the media outlets France Inter, France 2, Rue89 and Mediapart, among others. Those reports included investigative pieces alleging that workers at the company’s Socapalm and Safacam units, which operate palm oil plantations in Cameroon, were being exploited.
Since 2009, the Bolloré Group has brought more than 20 defamation suits involving over 40 reporters and nongovernmental organization activists in France, according to Sherpa, a French anticorruption organization that pursues humanitarian abuses by corporations. “Because of their systemic nature, we regard these legal actions as ‘gag suits,’” Sherpa said in a statement.
The Bolloré Group has said the suits were meant to combat what it described as biased reporting.
The judges will now decide whether Mr. Dorent and Mr. Alix should also be placed under formal investigation in France, the next step toward a possible trial. The case could still be dropped if the evidence is found lacking.