FRANKFURT (Reuters) - Volkswagen AG said on Thursday it would petition Germany’s constitutional court in an effort to overturn the appointment of a special auditor to investigate the actions of management in the “Dieselgate” emissions scandal.

FILE PHOTO - A Volkswagen logo is pictured at the International Auto Show in Mexico City, Mexico November 23, 2017. REUTERS/Henry Romero

A lower court appointed the auditor in November, in a victory for shareholder groups that want to establish whether VW bosses withheld market-moving information about the manipulation of vehicle-emissions tests.

The court in the town of Celle ruled that VW could not appeal, which the auto maker views as a violation of its fundamental rights, the Sueddeutsche Zeitung said in a report released in advance of publication on Friday.

The car maker will try to get the work of the auditor suspended before the constitutional court hearing, said the newspaper, which researched the report together with public TV channels NDR and WDR.

A company spokesman confirmed that VW would go to the constitutional court but did not elaborate. It was not immediately clear whether or when the constitutional court would take up the case.

Shortly after the Dieselgate scandal broke in September 2015, VW hired U.S. law firm Jones Day and advisory firm Deloitte to investigate the circumstances of its wrongdoing and who was responsible.

Although VW had pledged to improve transparency, it never published the findings that were used as the basis for a $4.3 billion settlement with the U.S. Justice Department.

Investor groups seeking billions in damages from VW are trying to establish when VW’s executive management board first became aware of cheating in the emissions tests and whether it disclosed possible financial damage to investors promptly.

German securities law requires companies to publish any market sensitive news in a timely fashion. The matter is also being investigated by German prosecutors.

VW has said it believes its management complied with obligations under German disclosure rules.

(This version of the story has been corrected to delete erroneous reference to share reaction to U.S. settlement in 6th paragraph)