Germany's development ministry said on Saturday that it suspended 21 million euros ($A24.97 million) in contributions to Rwanda's budget planned from this year through 2015.
Britain and the Netherlands already have suspended support and the US cut planned military aid.
A report by UN experts last month accused Rwanda of helping create, arm and support the M23 rebel movement in violation of UN sanctions. Rwanda denies the charges.
German Development Minister Dirk Niebel said he expects "unreserved co-operation" by Rwanda with the UN experts
"The accusations must be cleared up completely, and it must be clear that Rwanda does not support any illegal militias in eastern Congo," he added in a statement.