Turkey and the United Arab Emirates are carrying out regular and increasingly blatant violations of the UN arms embargo on Libya, fuelling a proxy war that is evading political solutions, a joint investigation by the Guardian has found. Flight data and satellite images show both nations using large-scale military cargo planes to funnel in goods and fighters to forces or proxies inside Libya, routinely violating the 2011 UN arms embargo despite political promises to abstain. In the nine-year conflict, Turkey has backed the internationally-recognised government in Tripoli with troops and weapons, while the UAE has bolstered opposing forces in eastern Libya led by General Khalifa Haftar. “The arms embargo remains totally ineffective,” said a diplomat with knowledge of a forthcoming annual report by the UN panel of experts on Libya, which is expected to focus on the violations. “In the case of those member states directly supporting the conflict, the violations are extensive, blatant and with complete disregard for the sanctions measures,” the diplomat added. Turkey and the UAE both attended a flagship summit in Berlin last January that was intended to halt foreign interference via flows of weapons, troops and money into Libya. Leaders from 11 countries attended the talks overseen by UN secretary general António Guterres and Germany’s chancellor Angela Merkel, aimed at halting fighting between the Tripoli-based Government of National Accord and the forces of Gen Haftar, who controls much of east Libya. Billed as a watershed, the summit was attended by France, Russia, Egypt, the US and the UK as well as Turkey and the UAE. Its main outcome was a proposal to sanction countries violating the arms embargo. But even as the conference was taking place, both sides were scaling up their efforts. As a result, observers say the UN arms embargo is all but defunct. These findings are part of a joint investigation tracking UK arms around the world, a collaboration between the Guardian, Bellingcat, and media nonprofit Lighthouse Reports. Lighthouse provided further information on Turkey’s use of military cargo planes, sourced in cooperation with German news outlets Stern and ARD, and Spanish newspaper El Diario. The UAE is using some of their fleet of C-17 Globemaster III’s, a “massive long-haul military transport aircraft”, according to manufacturer Boeing. Boeing and the UAE’s defence ministry did not respond to requests for comment. Flight radar data and satellite imagery show these aircraft flying regularly from Qusahwira, a desert airport in the UAE, to two remote military air bases, Sidi Barrani, in Egypt’s western desert region bordering eastern Libya, and Gianaclis, close to Alexandria. The planes travel from a military airbase to military institutions, piloted by the UAE military, eliminating any possibility that their mission is civilian. Satellite footage shows a rapid build-up of cargo capacity at Sidi Barrani airbase beginning in late 2019. The military airbases on Egypt’s border with Libya are key to UAE efforts to support Haftar’s Libyan National Army. “What’s on them is either transported by road or picked up by aircraft flying for Haftar,” said the diplomat. “The [UN] panel has written that this is indirect supply of arms and related material, which is a violation of the resolution,” they said, referring to the arms embargo. The Egyptian ministry of foreign affairs did not respond to a request for comment on the use of their airbases. The C-17s became an essential part of the air bridge between the UAE and Egypt after a crackdown on charter flights of Russian-made Ilyushin II-76 planes operating under the name Sigma Airlines in 2019, later replaced by Azee and Jenis Air. All three airlines were registered in Kazakhstan until spring this year, when Kazakh authorities investigated them for failing to provide paperwork proving they were complying with the arms embargo. In September, Kazakhstan stripped all three of their licenses. Sigma was sanctioned by the EU. Some observers complained that sanctioning the company name alone was unlikely to stop the flights in future. “Sigma will divest themselves of the aircraft – sanctions should be against the individuals in control of the aircraft themselves,” said the diplomat. Turkey has also used Airbus A400M military cargo planes to supply their forces on the ground in western Libya, in support of the Tripoli-based Government of National Accord. Flight radar data and satellite images of the planes show regular flights between Turkish airports in Istanbul, Gaziantep and Kayseri to Misrata throughout June, July and August 2020. Video footage posted on social media of men believed to be Syrian fighters chatting and lining up to board a plane in Gaziantep suggests that some of these flights transported mercenaries. “The Turkish air force used a new route to avoid certain flight information regions,” explained the diplomat. “All flights are nonscheduled or special charter flights that attempt to disguise their routes by switching their transponders off.” Turkey is extending the runway at Libya’s Al-Watiya air base, making it easier for large planes to land. A senior source at Turkey’s defence ministry told the Guardian that the country’s activities in Libya were focused on clearing explosives left by Haftar’s forces, providing humanitarian assistance and running hospitals. “All of Turkey’s activities related to Libya are within this framework and in accordance with international law,” they said. “There is no violation of any decision, sanction or international law. Our military flights are solely to transport essential materials needed by our staff in fulfilling their mission in Libya, among others for mine clearing, and medical and technical supplies for the hospital run by Turkey.” Russia has also committed open violations of the arms embargo. Satellite photographs of Russian MiG jets on the tarmac at the Al Jufra airbase in Libya were published by the US Africa Command in June. “These Russian aircraft are being used to support private military companies (PMCs) sponsored by the Russian government,” they added. An EU maritime force recently redirected a tanker carrying a large quantity jet fuel from the UAE headed to Benghazi in Libya, “likely” intended for military purposes. This week the EU froze assets of a Turkish firm, Avrasya Shipping, over allegations of embargo violations. “The arms embargo in Libya died many years ago,” said Claudia Gazzini, senior analyst on Libya with International Crisis Group. “What changed this year was that the violations of the embargo came out into the open more.” Gazzini said both sides have scaled up the arms flow to the conflict, creating a stalemate that had led to a lull in fighting, “The question is how do you transform that lull into an opportunity for reconciliation,” she said.