Thousands of German students face fines or fraud charges for supplying false information to obtain government grants.
A nationwide investigation by the finance ministry has concluded that every fifth student who applied for a Bafog grant supplied incorrect information about their financial circumstances.
Tens of thousands of students have been told they will have to pay back the grants received in 2000 and 2001 because they were awarded too much.
A ministry spokeswoman said: "Although we do not have fixed numbers yet, we believe tens of thousands of students pocketed too much. We realise that not all of those students knowingly supplied incorrect information, and they will not face any other consequences, apart from having to pay back the owed money."
The investigations began more than a year ago. The finance ministry and regional Bafog departments have checked the applications of 300,000 students who received the grants. Many students who were asked to pay back the money have done so.
The central public prosecutor's office had also said it suspected scores of Bafog recipients of intentional fraud, and hundreds had already been issued with €1,000 (£708) fines.
The Bafog grants are awarded to students who otherwise would not be able to finance their studies. Students must provide information about their financial situations and those of their parents.
Since July 2002, the maximum amount of assets a student can have in order to be eligible for a grant is €5,200. The maximum grant a student can be awarded is €446 a month and students are expected to pay back half of the grant after graduating.
The finance ministry is checking original Bafog applications against centrally compiled records to establish which students supplied false information.
The return of the grants is expected to yield at least €20 million.