French billionaire Vincent Bolloré was arrested and detained on Tuesday near Paris over allegations that he indirectly influenced election outcomes for governments in West Africa and secured lucrative port contracts for his company in return.

According to a report by the BBC, Bolloré, 66, who is the head of the Bolloré Group, was taken into custody as part of an ongoing investigation into how his company obtained contracts to operate the Lome and Conakry ports in Togo and Guinea respectively.

Specifically, investigators are looking into allegations that Havas, a communications consultancy and a subsidiary of Bolloré Group, had worked for Guinean President Alpha Conde and Togolese President Faure Gnassingbe for almost free, in the hope of receiving the container port contracts in return.

Upon his election, Conde swiftly terminated the contract of Conakry’s existing operator and gave it to the Bolloré Group. In a press release the group said it "formally denied” any wrongdoing in its African businesses.

The Bolloré Group has interests in construction, logistics, media, advertising and shipping.

Its African business, Bolloré Africa Logistics, is the biggest transport and logistics operator in Africa, where it has a network with 250 subsidiaries and almost 25,000 employees in 46 countries in Africa.

News of Vincent Bolloré’s arrest caused the group’s stocks to fall over 4 percent to 4.26 euros in mid-morning Paris trading.