Militants fighting in northern Iraq are selling oil from oilfields and refineries they have captured to local communities and smugglers, boosting their already strong finances, US intelligence officials have claimed.
At least some of the oil is used to fuel a power plant they seized after the radical Islamists captured large tracts of Iraq including the country's second city Mosul, killing thousands and causing hundreds of thousands to flee, the officials said.
The Islamic State now has "hundreds of millions of dollars" at their disposal, they continued.
Kurdish Peshmerga fighters have emerged victorious in the battle for Mosul Dam, but the question is - what will their next move be?
An ITV News team at Mosul Dam was with victorious Kurdish Peshmerga fighters at the complex earlier today.
ITV News joined a Kurdish unit fighting Islamist militants near Irbil and found them using tanks from the 1950s and short on ammunition.