Assad helped Isil earn €35m per month in oil sales
The Syrian government cut deals with Isil to help the jihadists earn more than €35m a month from the sale of oil, documents recovered from a US and British raid on a key commander have revealed.
Thousands of spreadsheets and accounts kept by the group's oil boss, Abu Sayyaf, which were retrieved in the biggest intelligence raid in US Special Forces' history last year, reveal how the two sides forged a mutually beneficial arrangement, despite being at war with one another.
Isil fighters captured some of the state's best-producing oil fields in eastern Syria in 2013.
Claims were reported two years ago that the regime had been purchasing oil from the jihadists, but the documents, which have been seen by the 'Wall Street Journal', show the scale of the collusion.
At the height of production, in late 2014 to early 2015, Isil recorded $40.7m (€35m) profit each month - the lion's share of which was made from sales to the Syrian government, according to the US Treasury Department.
One memo, itemised No. 156 and dated February 11, 2015, sent from Isil's treasury to Abu Sayyaf's office, requested guidance on establishing investment relationships with businessmen linked to the Assad regime.
The document cited existing agreements allowing trucks and pipeline transit from government-controlled fields through Isil-controlled territory.
Known only by his nom de guerre, Abu Sayyaf, a Tunisian who moved to Iraq after Saddam Hussein's fall, became close to a number of senior Sunni militants during the US invasion, including Isil founder Abu Bakr al-Baghdadi.
After Baghdadi established his 'caliphate' in June 2014, Abu Sayyaf was tasked with running its oil business from headquarters in the al-Omar field in Deir Ezzour near the Iraqi border. The documents reveal how, instead of getting rid of state employees at the fields after they had taken them over, Abu Sayyaf offered them handsome salaries to stay - sometimes up to four times the national salary.
According to the accounts of people of worked for him, he was a much-feared boss who would threaten his some 152 employees with beheadings or exile to Iraq if they disobeyed him. However, his work seems to have brought results and he became instrumental in helping it become the world's wealthiest terror group.
Spreadsheets show Isil's natural resource revenues in the six months to February 2015 amounted to $289.5m - some 70pc of which came from Abu Sayyaf's oil fields.
When the US-led coalition became aware of the huge profit-making operation, they began conducting air raids on its makeshift refineries.
The huge profits continued until Abu Sayyaf's death in a raid carried out by US Special Forces and the British SAS on his home in May 2015. (© Daily Telegraph, London)