A network of Colombian mercenaries backed by the United Arab Emirates (UAE) provided critical support to Sudan's paramilitary Rapid Support Forces (RSF), enabling it to capture the western city of el-Fasher last year, a new report says.

The investigation by security analysis organization the Conflict Insights Group (CIG) utilized data obtained by tracking the mobile phones of the Colombian fighters.

The UAE has long denied supporting the RSF, which has been fighting Sudan's regular army for three years.

El-Fasher's fall marked one of the most brutal chapters of the conflict, leading to the world's most severe humanitarian crisis with tens of thousands killed and millions forced from their homes.

The CIG has been vigilant in tracking evidence of Emirati military assistance to the RSF, but this research proves UAE involvement with certainty, according to director Justin Lynch.

“We are making public what governments have long known - that there is a direct link between Abu Dhabi and the RSF,” said Lynch.

The report illustrates how mercenaries coordinated drone operations from a UAE base prior to the RSF's takeover of el-Fasher.

Notably, Colombian President Gustavo Petro previously labeled these mercenaries as "spectres of death" and decried their recruitment as a form of human trafficking.

The findings come amidst ongoing discussions about foreign entanglement in Sudan's civil war, crucial for understanding the conflict's persistence and human cost.