"We must have clarity on these results, which are the opposite of what we expected," Le Drian told CNews on Thursday.
"The Catholic Church of Congo did its tally and announced completely different results."
Earlier Thursday the country’s electoral commission presented a delayed provisional count, naming Tshisekedi the winner with 38.57 per cent of the vote.
“Felix Tshisekedi is provisionally declared the elected president of the Democratic Republic of Congo," said Corneille Nangaa, the head of the Independent National Election Commission (Ceni).
This election, repeatedly delayed, has been controversial, as it would the country’s first transfer of power in 18 years, after long-term president Joseph Kabila said he would not seek re-election.
The candidate Kabila hand-picked to succeed him, former interior minister Emmanuel Ramazani Shadary, got 23.8 per cent of the vote, coming in third behind the other main opposition candidate, Martin Fayulu, with 34.8 per cent.
Vote tallies by Congo’s Catholic Church had Favulu as the winner, according to two diplomats briefed on the findings.
Fayulu, told RFI that the results were an "electoral coup”, adding that the provisional results “have nothing to do with the truth at the ballot box.”
Definitive results are due on 15 January with the new president sworn in three days later.
Police were deployed around the capital, Kinshasa, as the results were read out on national television.
DR Congo has never had a peaceful handover of power since independence from Belgium in 1960.
Tshisekedi, the head of the country’s largest opposition party, the Union for Democracy and Social Progress (Udps) told a crowd of supporters on Thursday that Kabila should no longer be seen as an adversary, “but rather, a partner in democratic change in our country”.