Diack, the former head of world athletics governing body the International Association of Athletics Federations - the IAAF - has been charged with corruption, money laundering and conspiracy.
Habib Cisse, legal advisor to the 82-year-old Senegalese official, also faces the same charges.
Police raided the IAAF headquarters in Monaco before charging Diack, who stood down in August when Britain's Sebastian Coe was elected as the new boss.
Later this month, the World Anti-Doping Agency (WADA) releases its report into allegations of widespread substance abuse in particularly in Russia and Kenya but also in other countries.
"Emanating from separate investigations by WADA's independent commission and the IAAF's own independent ethics commission into allegations surrounding its anti-doping rules and regulations, a French police investigation has now commenced," said an IAAF statement.
"The IAAF is fully cooperating with all investigations as it has been from the beginning of the process."
Diack was the IAAF president from 1999 until this year. It is alleged that he took bribes during the cover up of doping cases.
WADA has spent this year investigating allegations by the British newspaper the Sunday Times newspaper and German ARD broadcaster of widespread doping by Russian and Kenyan athletes. This was extended in August to consider allegations that the IAAF had failed to follow up suspicious tests by hundreds of athletes including world champions and Olympic medal winners.
WADA appointed its former leader Dick Pound to head an independent commission of inquiry.
"We expect the independent commission to deliver the findings of its report this month," WADA spokesman Ben Nichols told the French news agency AFP.
About 50 Russian athletes are currently banned by the IAAF, the highest number of any country. Fifteen Kenyans are serving suspensions for doping offences.
The latest 29-year-old Joyce Zakary and Koki Manunga, 21, were caught during the world athletics championships in Beijing.
Their suspensions cast a pall over Kenyan achievements at the championships. The country topped the medals table with seven golds, six silvers and three bronze.
One of the gold medals was won by David Rudisha in the men's 800 metres.
Coe, who claimed Olympic silver over the distance in 1980 and 1984, highlighted the IAAF's concerns about doping during a two-day visit to Russia this week to meet sports minister Vitaly Mutko and officials from the country's Olympic federation.
"I expressed my uncompromising position on the issue of doping in athletics and the importance for the sport to build trust and defend clean athletes at all times," said Coe.
He added: "I was able to meet and interact directly with Russian athletes, coaches and officials, and I appreciated their openness, passion for our sport and noted a real appetite for change."