A little-known company run by a distant relative of the Abu Dhabi royal family agreed to lend 12 billion euros ($12.9 billion) to South Sudan in exchange for repayment in oil, making it one of the largest ever oil-for-cash deals and the latest such intervention in a struggling African country.

According to an unpublished report by a United Nations Security Council-appointed panel of investigators reviewed by Bloomberg, the Dubai-based Hamad Bin Khalifa Department of Projects, or HBK DOP, and South Sudan’s then-finance minister Bak Barnaba Chol appear to have agreed to the terms of the loan in documents signed between December and February.