"Some people are using dead bodies... to say that we have killed civilians," a UN spokesman told the BBC.
On Wednesday, demonstrators calling for an end to violence put 17 bodies outside the UN building in Bangui.
They said the dead were innocent civilians killed in clashes between UN troops and armed groups.
But the UN says the dead were armed criminals who had been targeting peacekeepers and government soldiers.
"They shot at our peacekeepers and we returned fire," UN spokesman Vladimir Monteiro said. "The bodies resulted from the clashes."
whomA third whistleblower, who the Victoria Derbyshire programme met at a location in Europe, said a senior colleague had claimed that it was possible to barter medication for sex.
The UN’s environment chief, Erik Solheim, has resigned following severe criticism of his global travels and internal rule-breaking which led some nations to withhold their funding.
The Netherlands, Denmark and Sweden are among the countries that publicly said they were halting funding for Unep until the issues around Solheim were resolved. The total sum at stake is in the region of $50m, according to sources.