BERLIN, April 9 -- The Islamic State (IS) group has lost control over large oil fields in Iraq, which could deprive the terrorist group of an important income source, a German newspaper reported on Thursday.

Citing Germany's foreign intelligence agency BND, the newspaper Sueddeutsche Zeitung said the IS had lost "at least three large oil fields" in the country in the face of a large-scale Iraqi counteroffensive.

According to a BND report seen by the newspaper, satellite images from last month showed the group had set fire to two of the lost fields.

"In the eyes of the BND, it is proof that the IS itself does not believe in a quick recapture," the daily said.

The IS currently controls just one single oil field with a production capacity of around 2,000 barrels a day, which accounts for only 5 percent of the amount previously controlled by the extremist group, according to the report.

And oil fields held by the IS in Syriacould not help offset its loss in Iraq, added the report. In addition, the group lacks the technical expertise to operate those oil fields.

The BND came to the conclusion that the terrorist group "could hardly realize significant oil exports anymore", cutting off "one of its most important source of income."