UNITED NATIONS (Reuters) - Human Rights Watch on Tuesday acknowledged including erroneous testimony in a report alleging that rebels in Congo carried out summary executions, raped women and recruited children while receiving support from Rwanda, but said it stands by the report’s conclusions.

M23 rebels take position near the town of Mutaho, in eastern Democratic Republic of Congo May 27, 2013. REUTERS/Jonny Hog

Rwanda rejected the group’s allegations, saying that the inclusion of incorrect testimony in its press release on Monday undermines the entire report.

Rwanda also accused Human Rights Watch of paying for witness testimony, a charge the group denied.

The Human Rights Watch report came as Tutsi-dominated M23 insurgents clashed with Congolese government forces on Monday a short distance from Goma, the largest city in the Democratic Republic of Congo’s mineral-rich eastern region.

M23 provoked an international outcry last November when the rebels - with support from Rwanda, according to a United Nations Group of Experts - captured and briefly held Goma, a city of one million people.

A statement from Human Rights Watch acknowledged that its report contained an error based on the testimony of one of the sources it had interviewed.

“It said that Rwandan soldiers had served with the peacekeeping contingent in Somalia and Darfur. In fact, Rwandan peacekeepers served in Darfur but not in Somalia,” the statement said.

“We erred in including it because we ordinarily do not rely on only one uncorroborated witness in our publications. This was a mistake on our part.”

The rights group said that more than 50 witnesses had confirmed the key findings of its report about continuing Rwandan support for the M23.

“These findings are accurate and we fully stand behind them,” Human Rights Watch said.

Rwanda’s U.N. Ambassador Eugene-Richard Gasana said the error was far from minor. He said the report could not be taken seriously and should be withdrawn.

“They should correct the entire report. The entire report is a wrong one,” he told reporters, adding that Human Rights Watch had “zero credibility.”

Rwanda’s Deputy U.N. Ambassador Olivier Nduhungirehe told Reuters the error highlighted a flaw in Human Rights Watch’s working methods. “HRW pays for ‘testimonies’ and gets what it pays for,” he said. “It’s not an ‘error’ and merchandise sold can’t be returned.”

Human Rights Watch denied the Rwandan allegation. “Human Rights Watch does not pay witnesses in exchange for information, in order to preserve the integrity of the interviews we conduct,” said senior researcher Ida Sawyer.

The U.N. Group of Experts on Congo said in an interim report last month that Rwandan support for M23 had declined but continues. It also said that elements of the Congolese army had been cooperating with Hutu rebels linked to the 1994 genocide in Rwanda. Kinshasa and Kigali rejected this report.

Separately, U.N. Secretary-General Ban Ki-moon has asked Rwanda for evidence to support its allegation that U.N. peacekeepers have discussed collaboration with the same Hutu rebels the U.N. experts accused Congo’s army of cooperating with.