United Arab Emirates-based companies shipped nearly 11,000 tonnes of jet fuel to eastern Libya, the stronghold of the renegade general Khalifa Haftar, in a suspected violation of an international arms embargo, according to documents seen by the Financial Times. The shipment, under investigation by a UN panel of experts, had a market value of nearly $5m at the time it was loaded in the UAE and was delivered last month to the city of Benghazi, the headquarters of Gen Haftar’s offensive.

Stephanie Williams, the acting UN envoy to Libya, told the Ff that in the UN’s judgment the jet fuel was considered to be “combat supplies” and the shipment to eastern Libya could constitute a violation of the embargo. Diplomats have for months complained of what they describe as repeated and blatant violations of the arms embargo by foreign powers, including the UAE, backing the different sides in the Libyan conflict. The shipping and cargo documents seen by the Ff provide rare details on three of the companies that may be involved.

The documents state the supplier of the fuel was Afrifin Logistics FZE, based in Sharjah, one of the seven emirates that make up the UAE. It was loaded on to MT Gulf Petroleum 4, a Liberian-flagged tanker operated by Gulf Shipping Services FZC, the documents show.

UN officials confirmed the companies involved are registered in the UAE and the fuel was supplied in UAE territory but declined to confirm the names of the firms. UN investigations were ongoing to determine how the financial transactions were conducted and identify those involved, the officials said. The FT could not verify the authenticity of the documents.