Egypt has said it will investigate accusations that one of its officials called sub-Saharan Africans “dogs and slaves” during a conference in Nairobi.
The allegation has been made by a Kenyan diplomat, who says Egypt should be stopped from representing Africa in any negotiations.
But Cairo says there are no indications such language has been used, and has demanded any recorded evidence.
The case could raise tensions between Egypt and its sub-Saharan neighbours.
In a formal complaint, Yvonne Khamati, chairwoman of the African Diplomatic Corps Technical Committee, said the remarks were made by the head of the Egyptian delegation at the UN Environmental Assembly last week.
Divisions at the meeting arose after a resolution on Gaza was not passed due to lack of quorum, she said.
Consultations were then made by different delegations to discuss the issue. The comment, in Arabic, was made during talks with the Egyptian team, Ms Khamati said.
“[The comments] are uncivilized, undiplomatic, irresponsible, degrading and insulting,” she said in the document dated 29 May, which has been widely shared on social media.
She demanded an apology and that Egypt did not take any leadership position on behalf of Africa.
The Egyptian official has not been identified.
Egypt’s foreign ministry said in a statement that its minister, Sameh Shoukry, demanded an “immediate investigation to uncover the truth” and that the necessary measures would be taken.
“All of the information available to the ministry thus far indicates that no such language was used by the Egyptian representative,” the ministry said on its Facebook page.
“We reject any attempts to cast doubt on Egypt’s belonging to Africa and its defence of the continent’s interests,” it added
The ministry also said it would send a document to be distributed to all African countries “expressing Egypt’s rejection and denunciation of [Ms Khamati’s] exceeding of her mandate”.
Ties between Egypt and its sub-Saharan neighbours have been at odds over disputes including how River Nile waters should be shared by the countries it passes through.