The church, which has long pressed for a fair election in the largely Catholic nation, refused to name its "clear victor". Three diplomats briefed on the Church's mission said their findings clearly showed Fayulu had won.
The announcement of a victory by opposition presidential candidate Martin Fayulu (who the Catholic Church has indicated was the winner) is unlikely, but would pose high risks of looting by military elements and a coup attempt in Kinshasa.
The election may enable Congo to achieve its first peaceful, democratic transfer of power since independence in 1960.
He further said: "To all those who learned of the truth of the ballot boxes, especially to the Congo's National Bishops' Episcopal Conference, CENCO, and the Church of Congo, LCC, through your historical observations, we ask you to reveal to the Congolese people and to the whole world the name of the person who really was our people's choice". There were other organisations monitoring the elections, such as the Southern African Development Community, but it isn't clear yet if they agree or disagree with the electoral commission's provisional election results.
In order to do so they must appeal to Congo's constitutional court, which has 10 days to hear and rule on any challenges.
France too said Tshisekedi's win was "not consistent with the true results".
The DRC's powerful Catholic church says results tallied by its own election observers do not match the official ones.
There is also a rapidly developing story that the diploma in Marketing and Communications Tshisekedi may have submitted as a condition of his candidacy might not have existed.
Hopes rose on Wednesday that the Democratic Republic of Congo's election saga may have turned a corner after opposition leaders reached out to President Joseph Kabila. Fayulu got 6.37 million ballots, while Shadary obtained 4.36 million, he said.
"How long are we going to negotiate results?"
The global community has not congratulated Tshisekedi on his victory. In 2011, Etienne Tshesekedi's victory was stolen.More news: Brett Brown: Jimmy Butler Didn't Cross the Line in Film Session
Kabila last year announced he would step down after 18 years in power and then hand-picked a loyalist, former interior minister Emmanuel Ramazani Shadary, to be his party's candidate in the December 30 poll.
Given that Kabila was reluctant to leave office after the Constitution required that he do so, many believed he would ensure that Shadary was elected.
"We must have clarity on these results, which are the opposite of what we expected", Le Drian told CNews on Thursday. Belgian Foreign Minister Didier Reynders said his country planned to raise concerns at the U.N. Security Council.
In a pre-dawn announcement, election officials named Tshisekedi, son of the country's long-term opposition leader, provisional victor of the troubled vote to replace President Joseph Kabila.
"The Catholic Church of Congo did its tally and announced completely different results". The United States threatened sanctions against officials who rigged the vote. Dozens of polling centers opened hours late as materials went missing. Some observers said the barred voters could have made the difference.
The government has cut internet service since the day after the election to prevent speculation on social media about who won, and blocked some radio stations.
Some Congolese tired of Kabila's 18-year rule, the two turbulent years of election delays and years of conflict that killed millions of people said they simply wanted peace.
Even as Tshisekedi and his supporters celebrate their victory, Fayulu was arguably the most important candidate in these elections. He is barred from serving three consecutive terms, but until he announced a year ago that he would step aside many Congolese feared he'd find a way to stay in office.
Now Congo faces a new leader who is little known after spending many years in Belgium and living in the shadow of his outspoken father.
"There's no spirit of revenge", said Felix Tshisekedi, the candidate of the longtime opposition UDPS party.
UN Secretary General Antonio Guterres urged all sides "to refrain from violence and to channel any eventual electoral disputes through the established institutional mechanisms", his spokesman Stephane Dujarric said.