The Competition and Consumer Protection Commission has concluded an investigation into Volkswagen Group's understatement of carbon dioxide (CO2) emissions on certain cars.

This is separate to the ongoing investigation into the admission by the car giant that it fitted cheat devices to 11 million cars in order to mislead official tests for nitrogen oxides (NOx).

The CO2 investigation was initiated last November after the car firm found, during its internal investigations into the NOx scandal, that it had provided “incorrect declarations” on CO2 for some cars. This affected only certain new models on sale this year and all customers involved were given the opportunity to cancel their purchase without cost. The CCPC has concluded its investigation, finding the car firm acted appropriately in this instance.

The main CCPC investigation into VW Group relates to the fitting of devices designed to mislead official tests for levels of NOx. This affects an estimated 115,000 motorists in Ireland across a variety of VW Group brands.

This investigation is ongoing and in a statement the CCPC said it will “require in-depth analysis and therefore there is no timeline as to the conclusion of this investigation.”

In total 11 million cars worldwide are affected by the cheat device scandal. VW Group is currently in the process of recalling the various model affected. The fix requires a software update.

Legal proceedings are also underway against the car giant, in Ireland and internationally. On Tuesday a district court in Co Mayo granted an interim preliminary order for discovery in a claim for damages by a Roscommon woman against Volkswagen Ireland and its German parent company Volkswagen AG. Her solicitor in the case, Evan O'Dwyer, said at an earlier hearing that he is also representing 87 other customers in Ireland who plan to take cases against VW over the emissions scandal.