Members of the European Parliament are investigating why millions of dollars of EU funding for African peacekeepers in Darfur is not reaching the soldiers.
African Union peacekeepers have been unable to end the fighting
The leader of a recent delegation to the troubled western Sudanese region, Josep Borrell, said African Union troops had not been paid for months.
Since the force deployed in 2004, the EU has contributed 282m euros ($386m).
Mr Borell also described the ethnic conflict, in which some 200,000 people have died, as a "devil's brew".
The Spanish MEP also said the AU troops were "ineffectual" in stopping attacks on the civilian population.
Mr Borell said his delegation had discovered that the money set aside to pay soldiers in the AU peacekeeping force was not getting through.
"We're in a situation which is very embarrassing," he said.
"For months they have not received their pay. Some have not received any pay at all."
Mr Borell said EU officials would travel to the AU headquarters in Ethiopia and also speak to the force's commanders in Nigeria to find out why.
He described the 7,000-strong AU force as "ineffectual", because they have no mandate to act when there are attacks on the civilian population.
"They find themselves obliged to stay back at their bases," he explained.
The AU force is due to be replaced at the end of next year by a new combined peacekeeping force of African and UN troops.
However, MEPs have said it will be too late and have called on the EU to put more pressure on Sudan to allow a speedier deployment.