Prosecutors who have unravelled a widespread scam that involved handing out driving licences for cash payments claim that GNR officers were involved.
The focus of the investigation is the test centre in Vila Verde, Braga where students with enough cash could by their full driving licence.
The National Association of Driving Schools is involved in the investigations where corruption seems to have been endemic with 47 individuals accused of taking part in the bent scheme.
Between 2008 and 2013, the six principal defendants profited by a minimum of €1,107,000, claim the state prosecutors.
The accused are examiners, driving instructors and a group of Braga GNR officers.
Students wishing to guarantee a pass in the theory exam could hand over €1,500 instead of sitting the paper.
The practical driving test could be passed by a more reasonable €100 to €150 with money for both parts of the test being divided up and shared by those involved in the scheme.