Russian authorities are reportedly paying Iran $4.5bn a year to import Shahed drones to use in Ukraine, a leading US thinktank has said. 

In its daily report on the conflict, the Institute for the Study of War said a group of hackers made the claim after it infiltrated servers belonging to a company linked to the Iran Revolutionary Guard Corps. 

“The leaked documents suggest that Russia pays $193,000 per Shahed-136 drone in batches of 6,000 drones, which would total about $1.1bn for all 6,000,” it said. 

“Another type of Shahed-238 reportedly costs about $900,000 per drone and Russia reportedly plans to purchase 2,310 per year for just under $2.1bn,” it added. 

It also details how Moscow reportedly pays another $1.4m per unit of another type of drone and plans to purchase 677 of them. 

 “A Russian milblogger justified the high cost due to the risk that Iran assumes by selling these drones to Russia and noted that all documents indicated that Russian plans to further localise production of Shaheds,” it added.