The Catholic Church in the Democratic Republic of Congo has been called 'irresponsible' after claiming there was a clear winner in last Sunday's presidential election.

Twenty-one candidates went head to head in the December 30 poll to decide the successor to President Joseph Kabila, who has been in power since 2001.

The result was due to be announced on Sunday but the electoral commission has said this could now be delayed until next week. 

CENCO, the bishops' conference of the Catholic Church in the DRC, said on Thursday that its own tallies from more than 40,000 observers had revealed one winner, although it did not disclose who this was. 

'We call on the CENI ... to publish, with all responsibility, the results of the election that respect truth and justice,' Donatien Nshole, secretary general of CENCO, told reporters.

On Friday, the ruling coalition accused the Catholic Church of behaving in an 'irresponsible and anarchic' way over its claims, Reuters reports.

The coalition 'firmly deplores...the partisan, irresponsible and anarchic attitude of CENCO', said Barnabe Kikaya Bin Karubi, an adviser to outgoing President Joseph Kabila and a spokesman for Kabila's candidate, Emmanuel Ramazani Shadary.

'This seriously violates not only the constitution but also the electoral law,' he added. 

Kikaya told Reuters that Kabila had met Catholic bishops on Friday but did not reveal any details of their discussions. 

Electoral commission president Corneille Nangaa also accused CENCO of trying to start an insurrection. 

'The announcement of voting trends by Priest Nshole is likely to brainwash the population while preparing an insurrection that Cenco alone will be responsible for,' Nangaa wrote in a letter to Cenco president Marcel Utembi.

While the government and electoral commission both say the election was fair, the opposition is claiming irregularities.

There are fears that a disputed election result could lead to unrest in the country, prompting the US to deploy troops to Gabon.  The government has also taken the unusual step of cutting the country's internet, claiming the measure was to prevent 'chaos' ahead of announcing the poll result.

Ravina Shamdasani, spokesperson for the UN's High Commissioner for Human Rights, said on Friday that oppsition candidates were experiencing harassment and that cutting off the internet was a civil rights violation. 

'Intimidation and harassment against journalists, opposition candidates and human rights defenders continues to take place,' she said.

'This being a very sensitive, a very tense period, we are concerned that these efforts to silence dissent could backfire considerably when the results are announced.

'We are watching carefully, and we are calling on all sides to refrain from the use of violence.'