It accused Germany of engaging in "antagonistic activism" after the United States in December recognized Moroccan sovereignty over the territory, which is also claimed as an independent state by the Algeria-backed Polisario Front movement.
Washington's decision, part of a deal that also involved increasing diplomatic ties between Morocco and Israel, prompted Germany to call a UN Security Council meeting to discuss the issue.
In March, Morocco ordered all governmental departments and bodies to abstain from any cooperation and contacts with the German embassy and German political organizations.
Morocco also said Germany had disclosed sensitive information provided by Moroccan security services to a convicted jihadist, without elaborating.
It also repeated a previous complaint that Germany had not invited it to a 2020 Berlin conference on Libya. Morocco has over the past year played a role in Libyan diplomatic negotiations by hosting talks between members of the rival parliament groups.The German embassy in Rabat was not immediately available to comment.