The billionaire was taken in for questioning by police in Nanterre, just outside Paris, on Tuesday in connection with an inquiry that began in 2016 with a raid on the conglomerate's headquarters in nearby Puteaux.
Also detained were former Bolloré executive Gilles Alix and Jean-Philippe Dorent, head of international relations at Bolloré's advertising and PR company, Havas.
The Bolloré group is suspected of undercharging for Havas's services in order to win contracts to run container ports in the two countries' capitals, Lomé and Conakry.
Togo election campaign
Dorent ran part of the 2010 election campaign of Alpha Condé, who had returned home from exile in Paris, where he established friendly relations with then foreign affairs minister Bernard Kouchner and with Vincent Bolloré himself.
After taking office Condé scrapped the 25-year container port contract with a subsidiary of another French company, Necotrans, and awarded it to Bolloré.
Necotrans launched legal action in France.
Despite being awarded two million euros to settle the case, the company ended up declaring bankruptcy, with Bolloré buying some of its shares at a reduced price in 2017.
Dorent described the idea that his participation in the election campaign led to winning the contract as "a fantasy" in an interview with Le Monde newspaper last year.
Speaking to the same paper a year earlier, Condé was unapologetic.
"Bolloré fulfilled all the conditions of the tender," he said. "This is a friend. I favour friends. So what?"
Togo container port
Dorent also did PR work for Togo's President Faure Gnassingbé after he succeeded his father, Gnassingbé Eyadema.
When Gnassingbé was reelected in 2010, he awarded the Lomé container port contract to Bolloré, a decision that also gave rise to legal action by another French bidder, Jacques Dupuydauby, who had previously worked with the company in Togo.
Documents seized during the 2016 raid corroborate the undercharging hypothesis, sources have told Le Monde.
Bolloré, Guinea deny allegations
"The Bolloré group categorically denies that its subsidiary at the time SDV Afrique committed any irregularities," the company said in a statement on Tuesday. "The services relating to these bills were carried out in total transparency."
The accusations "have no economic basis and reveal total ignorance of this industrial sector", it said.
The Conakry contract was awarded in strict accordance with the law, Guinean government spokesman Dmanatang Albert Camara said.
The accusations make no sense, he added.