The U.N. inspection team has reportedly collected a “wealth” of evidence regarding the use of chemical weapons by the government of Bashir al-Assad…but will not actually make a direct accusation against it.

Three U.N. diplomats connected to the investigation have told Foreign Policy magazine the team will present a very strong circumstantial case pointing strongly in the direction of the Syrian government.

“I know they have gotten very rich samples — biomedical and environmental — and they have interviewed victims, doctors and nurses,” a Western official told FP. “It seems they are very happy with the wealth of evidence they got.”

Syria and their main ally Russia have repeatedly claimed the Assad government was behind the chemical weapon attack.

Diplomats have said the inspection team was only authorized to conclude if weapons were used and not to assign blame as to the entity using the weapons.