It is understood the terror insurgents managed to extort a staggering £550million from the people forced to live in their vile empire as the group loses the oil revenues needed to fund its unholy war.
There are eight million people currently under the control of the demented terrorists – who managed to rake in £1.67billion last year after starting to mint their own currency.
The reports says: "ISIS' military defeat is not imminent... as things stand, ISIS’ economic collapse remains some way off in the mid-term."
The revelations show the twisted terror cell is operating with bizarre levels of bureaucracy in a bid to survive the onslaught of Western air strikes and local militias.
One of the report's authors, Jean-Charles Brisard, told CNN: "What strikes me is the fact that they're clearly behaving as managers, not simple looters.
"They really have budget requirements, and they're compensating."
The unified international bombing campaign spearheaded by British, Russian and US forces has taken its toll on the terror death cult, cutting down on the twisted state’s land, oil and capital.
And the report gives the clearest indication yet that the group are depending on taxation to survive.
Earlier this year US and British security officials revealed that strategic strikes on oil and cash within the terror regime was forcing the terror cult to find other ways of making cash.
Air Vice-Marshal Edward Stringer, the senior UK official responsible for undermining ISIS' finances, said: “What we are now seeing is that they are running short of cash and they are looking for more imaginative ways to do things.
“It is early days, but only in the last week we have heard from the sources that we have that the taxation system is becoming more arbitrary, more looking to fines, and so becoming less progressive and less easy to sell to the population.”
Meanwhile the coalition claims its intelligence has outflanked the terrorists to the point they are able to find where the terror group is storing cash, right down to the room it is being kept in.
Maj Gen Gersten added: “We believe we have removed hundreds of millions from circulation.”
The gangster methodology of fighters desperate to fund their sickening war is making it harder for them to paint the brutal caliphate as a positive regime to would-be terrorists, with Vice-Marshal Stringer adding: “ISIS is trying to get more hard cash through extortion of the local population.
“We are starting to see corruption and embezzlement among senior leaders, suggesting we are having success,” Express reported.
212-11