Inquiries by Bevan's team indicated that the factory orders could be traced back to the United States and Saudi Arabia. Ammunition was then shipped to southern Turkey en route to opposition groups in northern Syria.
"Their procurement networks reach out into southern Turkey and they obviously have a series of very strong relationships with very big distributors," Bevan told the BBC.
The ammunition then found its way into Daesh hands, eventually ending up in Iraq, where Daesh is fighting US-backed government troops. Ammunition boxes in question were found starting late 2015 in Tikrit, Ramadi, Falluja and Mosul, according to CAR.
Daesh, a militant jihadist organization outlawed in many countries, including the United States and Russia, took over vast swathes of Syria and Iraq in 2014 amid the ongoing Syrian civil war.
The US Train and Equip Program aimed at moderate Syrian rebels was canceled in October 2015 after a number of US-trained forces were quickly overrun by extremists while the US-provided weapons were reportedly handed over to the terrorist groups. A part of the US-trained forces defected and fought on the side of terrorists.
Both the United States and the United Kingdom have recently decided to resume training programs in Syria.