According to a confidential UN investigation into a deadly rocket attack on the migrant detention centre in Libya was caused by the fighter from another country.
No country in the report is not named, but a source close to the investigation said it focused on the United Arab Emirates. UAE did not respond to a request by the BBC to comment on the message.
The result of the July attacks killed 53 migrant and 130 were injured, a UN spokesman called it a potential war crime. It is believed that most of those killed in the migrant detention centre in Tajura East of the capital Tripoli were Africans from the regions South of the Sahara, who were trying to get from Libya to Europe.