HEILBRONN, Germany (Reuters) - A German judge has condemned the lack of transparency over Volkswagen's VOWG_p.DE emissions scandal and said the dearth of information was obstructing the settlement of a related case brought by a former employee of VW subsidiary Audi.

FILE PHOTO - A Volkswagen logo is pictured at the newly opened Volkswagen factory in Wrzesnia, Poland, September 9, 2016. REUTERS/Kacper Pempel/File Photo

Ulrich Weiss, former head of diesel engine development at Audi, is suing the carmaker for wrongful dismissal and re-employment after he was fired in February after investigations into the scandal which broke in September 2015.

Audi has said a decision over whether Weiss could be re-employed cannot be taken until U.S. law firm Jones Day, hired by VW to investigate the scandal, has clarified his role and published a full report on its inquiries.

But parent VW, which initially had pledged maximum transparency, has since decided not to disclose the findings of Jones Day although key parts were compiled in the form of a “Statement of Facts” for the U.S. Department of Justice.

Audi’s lawyers used a hearing of the Weiss lawsuit before a labor court in Heilbronn in southern Germany on Tuesday to emphasize that there neither is, nor will be, a written report by Jones Day - an argument dismissed by the judge.

“I don’t believe that,” judge Carsten Witt said. “There are definitely written statements,” he said, adding the case may need to be handed over to the Federal Labour Court, Germany’s top legal authority for labor disputes.

The decision not to publish the results of the Jones Day-led investigations is “disconcerting” and “irritating”, Witt said.

The U.S. law firm as well as offices at Audi’s and VW’s headquarters were searched last month by Munich prosecutors. A complaint by VW to prevent prosecutors from using any material seized during the raids was rejected on Monday by a Munich court.

Audi admitted in November 2015 that its 3.0 liter V6 diesel engines were fitted with an auxiliary control device deemed illegal in the United States that allowed vehicles to evade U.S. emission limits.

VW in December agreed to a $1 billion settlement to fix or buy back about 80,000 polluting diesel vehicles sold in the country.

Separately, Audi lawyer Martina Hidalgo said the carmaker will make an offer to Weiss in early May regarding compensation. The former long-time engineer is seeking 6 million euros ($6.4 million) of severance pay.