A Russian military aircraft stealthily flew the cash and three munitions models – a British NLAW anti-tank missile, a US Javelin anti-tank missile and a Stinger anti-aircraft missile – to a Tehran airport in the early hours of August 20. the source told Sky News, speaking on condition of anonymity to share sensitive information. The weapons were part of a shipment of UK and US military equipment destined for the Ukrainian army that “fell into Russian hands”, according to the source. The source said they could give Iran’s Islamic Revolutionary Guard Corps (IRGC) the ability to study Western technology and possibly copy it. “They will probably be reverse engineered and used in future wars,” the source said. For its part, Iran supplied Russia with more than 160 unmanned aerial vehicles (UAVs), including 100 Shahed-136 drones, the source claimed. These are nicknamed “suicide drones” because they explode on impact. The source claimed a further €200m (£174m) drone deal had been agreed between Tehran and Moscow in recent days. “This means there will be another large supply of UAVs from Iran soon,” the source said. The governments of Iran and Russia have been approached for a response to the allegations. President Vladimir Putin’s forces have recently stepped up drone strikes against Ukraine. Use Chrome browser for more accessible video player 3:34 Russian use of Iranian drones in Ukraine Coupled with more conventional missile attacks, they have targeted critical energy and water supplies across the country, including the capital Kiev. The barrages have killed civilians, caused widespread blackouts and stretched Ukrainian air defenses, with expensive anti-aircraft missiles deployed to counter much cheaper drones. Read more: What are Iranian kamikaze drones and will the US send the deadly MQ-9 Reaper? Iranian drones ‘critical part’ of war effort Justin Bronk, a senior researcher at the Royal United Services Institute, a London-based think tank, said Iranian drones have become a critical part of Russia’s war effort. “Had Iran not supplied the Shaheds, it would have been significantly less effective in terms of the Russian strike campaign against Ukrainian electrical and water infrastructure,” he said. In a potentially even more serious threat, the Iranian government has also reportedly agreed to transfer larger, more sophisticated ballistic missiles to Russia. Vadym Prystaiko, the Ukrainian ambassador to the UK, said that if the reports were confirmed “this would be a real, real threat”. He told Sky News: “If [Iranian ballistic missiles] Come in numbers, we’re going to have real problems.” Use Chrome browser for more accessible video player 0:29 Zelenskyy warning about Iran’s drones Iran dismissed the missile claim as “totally false”, although it eventually admitted that it had supplied Moscow with a “limited number of drones”. However, Foreign Minister Hossein Amirabdolakhian argued on Saturday that this happened before – not since – Russia launched its full-scale invasion of Ukraine in February. Instead, Ukraine, the US, the UK and France have accused Iran of supplying drones to Russia more recently. The exact total number is not clear. The US said in July it believed the Iranian government was preparing to provide Russia with hundreds of drones. Russian military cargo planes ‘in Tehran’ Offering evidence of the alleged drone transaction on August 20, the security source shared with Sky News satellite images they said showed two Russian military cargo planes at a Tehran airport. The source said one of the Ilyushin IL-76 aircraft was believed to be carrying the €140m (£122m) and Western weapons seized. Image: 1.17 am local time – satellite image shared with Sky News shows two planes at Mehrabad International Airport The first image, time-stamped at 1.17am on August 20, showed two aircraft, with red lines, at Mehrabad Airport in the Iranian capital. In the second image, taken just after 3.30am, one of the aircraft had moved to the runway side of the facility and the other had turned around. Image: 3.32am local time – satellite image shared with Sky News shows two planes have moved into Tehran’s main airport In the final image, three and a half hours later, both aircraft appeared to be gone. Either one or both departed carrying Iranian drones, the source said. Image: 7.01am local time – satellite image shared with Sky News shows planes gone from Iranian airport The source said they were aware of at least five Russian aircraft carrying drones from Iran since August 20 as part of the deal. A list of drones provided As for what Iran supplied, the source said: 100 Shahed-136 drones, 60 smaller Shahed-131 drones and six Mohajer-6 drones. Unlike the Shahed “suicide” aircraft, the Mohajer-6 is an armed drone that can drop or launch munitions. Asked why Russia also gave Iran captured British and American weapons, the source said it was believed to be because Tehran wanted to use its ability to reverse engineer products. The source said they believed knowledge gained by the Iranians from reverse-engineering a US spy drone captured by Iran in 2011 helped develop the Shahed drones. Iran reverse engineering drones “We believe that the Iranians have demonstrated that they have an effective reverse-engineering system, as we can see with the UAVs they have reverse-engineered from the US UAV captured in 2011,” the source said. “It seems that Iran also wants to profit from the war [in Ukraine] taking from the Russians western capabilities that will be useful to them in the future – as has happened in the past.” A US RQ-17 Sentinel surveillance drone – used for reconnaissance – was seized in December 2011. An Iranian commander claimed the following year that his country had converted the aircraft and was building a replica. Moscow last month denied that its forces had used Iranian drones to attack Ukraine. “Russian equipment with Russian nomenclature is being used,” spokesman Dmitry Peskov was quoted as saying on October 18. “All further inquiries should be directed to the Ministry of Defence.” Sky News has contacted the Russian Ministry of Defense but has yet to hear back.