UNITED NATIONS - Rwanda has refused to issue entry visas to two members of a U.N. expert panel that accused Kigali last year of arming rebels in eastern Democratic Republic of the Congo, describing them as biased, Rwandan and other diplomats said on Tuesday.

Several U.N. diplomats, speaking on condition of anonymity, disputed the allegations of bias.

The U.N. Security Council's Group of Experts, which monitors compliance with sanctions and an arms embargo on Congo, said in a report last year that Rwanda's defense minister was commanding the M23 revolt in Congo and that Rwanda was arming the rebels and supporting them with troops. It also accused Uganda of supporting M23.

Rwanda's government was furious about the experts' report, as was the Ugandan government, and denied the allegations. U.N. officials and Security Council diplomats, however, said the Rwandan denials were not credible.

A Rwandan diplomat confirmed the refusal to issue entry visas to Bernard Leloup of Belgium and Marie Plamadiala of Moldova. Several council diplomats dismissed the Rwandan allegations of bias, saying they suspected Kigali may be getting revenge over the group's revelations about M23's Rwandan links.

"We told the DRC (Congo) sanctions committee ... that no visa will issued to both of them," Rwanda's deputy U.N. ambassador, Olivier Nduhungirehe, told Reuters. He was referring to the Security Council's Congo sanctions committee.

Several diplomats said the other four members of the expert group are currently in the Rwandan capital Kigali for discussions with the government regarding the panel's continued investigation of Rwanda's role in supporting M23.

Britain, France and the United States are among the countries that have urged Kigali to cooperate with all six members of the expert panel, council diplomats said, adding that they hoped Rwanda would relent.

Last year's report by the Group of Experts caused significant grief for Rwanda. The United States, Sweden, the Netherlands, Britain and the European Union reacted to the experts' accusations by suspending some aid to Rwanda, which relies on donors for about 40 percent of its budget.

Accusations of bias

The Rwandan U.N. mission prepared a memo complaining about Leloup and Plamadiala. In that memo, obtained by Reuters from a diplomatic source, Rwanda accused Leloup of "a clear pattern of a deeply-seated bias against the GoR (government of Rwanda)."

The memo said Plamadiala has "no demonstrated expertise" suitable to being a member of the expert panel and "demonstrates inappropriate professional boundaries not befitting a U.N. expert."

Despite Rwanda's complaints, U.N. Secretary-General Ban Ki-moon reappointed Leloup and Plamadiala to the expert group.

The U.N. press office did not have an immediate response to the question of whether the Rwandan memo complaining about the two experts had been received by Ban's office.

Plamadiala declined to comment in an email to Reuters. Leloup did not respond to an emailed request for comment.

Last year, Rwanda accused the Group of Experts' coordinator, Steve Hege of the United States, of bias and leaking information to the media. Several council diplomats told Reuters those allegations about Hege were unfounded. The experts' new coordinator is Emilie Serralta of France.

Recently the M23 rebellion started to implode, U.N. diplomats and officials say. Hundreds of Congolese M23 rebels loyal to warlord Bosco Ntaganda fled into neighboring Rwanda or surrendered to U.N. peacekeepers over the weekend after being routed by a rival faction.

Ntaganda, the fugitive Rwandan-born former Congolese general, walked into the U.S. Embassy in Rwanda on Monday and asked to be transferred to the International Criminal Court, where he faces war crimes charges racked up during the rebellion.

African leaders signed a U.N.-mediated regional accord late last month aimed at ending two decades of conflict in eastern Congo and paving the way for the possible creation of a U.N. intervention force to combat armed groups.

Reuters