The FIA has confirmed that the turbo on Mikko Hirvonen's Citroen DS3 WRC was illegal during the Rally of Portugal earlier this month.
The Finn had already been excluded from the event, losing what would have been his first win for Citroen and handing the victory to Ford privateer Mads Ostberg, for an infringement on the car's clutch, but the post-event scrutineers also found fault with the dimensions of the turbine wheel in the turbo.
The unit from Hirvonen's car was sent away for further investigation and the FIA ruled on Saturday that the part was illegal and the rally winner would have been excluded for that issue regardless of the clutch infringement.
The stewards' decision from the event stated: "The stewards decide to confirm the penalty of exclusion of car number two from the results of the Rally of Portugal, including all stage times for technical non-compliance."
The secondary test of the turbo unit had been taken to clarify the original decision and to ensure that the testing equipment was correct. The dimensions of the turbine wheel were again found to outside of those permitted.
The stewards' statement added: "A competing car is required to comply with the homologation papers and in this case there were two aspects being the clutch plate and the turbine wheel in which it failed to meet this requirement."
Citroen confirmed it would not be appealing the decision. The FIA will not be taking any further action against the team.