Employment Minister Mette Frederiksen (S) has been accused of misleading parliament.
Frederiksen used the results of a large research project about employee absenteeism as documentation to back her reform policies.
Experts now say that Frederiksen manipulated the data that she showed to parliament so that it would prove the points that she wanted to make.
The case stems from a large trial called 'Back to Work' participated in by 22 councils. A multidisciplinary team of doctors, psychologists and social workers collaborated on the project designed to get sick workers back on the job faster.
A 2012 evaluation of the report said that that "the net result on sick leave time across all of the councils was zero". Economic benefits of the programme were also judged as negligible.
Nevertheless, the Employment Ministry issued a statement saying that the "groundbreaking study shows the way to lower absenteeism".
READ MORE: Yet another minister admits lying to parliament
The minister claimed that the data showed that early adoption of the multidisciplinary approach to sick leave could save 8,700 kroner per case. Critics said that conclusion was based solely on the five municipalities that realised good results from the study.
One of the researchers behind the report had cautioned that it was "quite misleading to show only those numbers".
Enhedslisten spokesperson Christian Juhl called Frederiksen's actions "scientific chicanery" and "insane" and has called Frederiksen in to discuss the matter.
The employment minister admitted that her analysis may have been imprecise.
"If there are doubts about information that I have received as minister, then it is correct to look more closely at the case," Frederiksen told Jyllands-Posten newspaper.
